Research Tendency of Digital Marketing in the Period Of 2011 – 2022: a Bibliometric Analysis

Digital marketing considered as an alternative of marketing strategies in the digital era since the technology has developed rapidly. This study aims to present a bibliographic as well as a bibliometric review regarding to the emerging tendency of digital marketing. A bibliometric analysis used to conduct this research involving performance analysis, science mapping, and network analysis. A few of software such as VOSviewer and Publish or Perish (PoP) utilized in analyzing the document which published during 2011 to 2022 from the Scopus database. The results of this study showed that in the period 2011 – 2022, there were 43 publications and 336 citations regarding the digital marketing, however the development of publications and citations roundly fluctuated. Hereinafter, mostly, some marketing strategies such as e-marketing and b2b marketing were usually used in the digital era. Nowadays, generally, social media and internet had been utilized widely in the business field. It proves that social media and internet extremely help the entrepreneur in conducting the digital marketing. In addition, tourism was one of the business fields employing the digital marketing to advertise the tourism service. Also, qualitative research was the methodology trend employed in carrying out the research regarding the digital marketing. Mostly in the Covid-19 pandemic, the digital marketing was employed to advertise the goods or service to the consumers


INTRODUCTION
The fast spreading of technology in the 21st century presents some benefits on many aspects in life (Sanabria & Arámburo-Lizárraga, 2017;Silber-Varod et al., 2019).One of aspect in life is business in which to achieve the successful business, there are some factors that have to be considered, namely: innovation, marketing, operation, and finance (Saura et al., 2021).It shows that marketing is one of the important factors to obtain the success in business.To compete in promoting the products such as goods and services, entrepreneurs have to apply precise marketing strategy.Some literatures revealed that digital marketing assumed as the most crucial marketing strategies in the digital era because the technology development in 21st century supports it (Adam et al., 2020;Fedoryshyna et al., 2021;Kitsios et al., 2021;Rahim et al., 2020;Souza et al., 2021).
Digital marketing becomes the marketing trend in the business field in which before the goods are distributed to consumers or the services are provided to clients, they are digitally advertised in several online platform (Miklosik et al., 2019;Tomic & Supin, 2019).This marketing strategy provides the concept of effectiveness and efficiency in the business because it can reach out the numerous consumer and interest them to use the goods or services (Kitsios et al., 2021;Souza et al., 2021).As a consequence, the digital marketing is extremely suitable to the business trend of goods and service at the moment.To date, the research dynamics, however, related to the digital marketing is not clear.Therefore, a review that can provide clear information regarding the research trends of digital marketing is needed.Donthu et al. (2021) argued that the bibliometric analysis as the method which support the review the enormous document about the certain research.It indicates that bibliometric analysis is able to be employed in this study to provide clear information related to the research of digital marketing development.
This current study aims to present a bibliometric and bibliographic review associated to the emerging tendency in the digital marketing.Particularly, these research questions will directly guide this study: 1.How is the relation of publication-and-citation connected to the metric of digital marketing studies? 2. How is the publication and citation tendency of digital marketing studies? 3. What are the most frequent emerging keywords related to the digital marketing studies?How lis lthe ldistribution lof lthe lmost lemerging lkeywords lin lthe latest lperiod?

LITERATURE REVIEW
To date, several bibliometric analysis research have studied the digital marketing (Donthu, 2021;Faruk et al., 2021;Kim et al., 2019;Krishen et al., 2021;Kumar et al., 2019;Othman, 2021;Saheb et al., 2021).Donthu et al. (2021) only studied the digital marketing from one source that is Asia Pacific Journal of Marketing and Logistics.Meanwhile, Saheb et al. (2021) studied the development of digital marketing form many literatures using quantitative analysis.On the other hand, Othman et al. (2021) studied the research development of digital marketing using the Facebook media.In addition, some literatures studied the journal, and 6) the status of publication stage was final.The selection of inappropriate documents based on linclusion lcriteria lis lshown lin lTable 1.
Table 1.The Selection Process of Document Thus, there were only 43 remaining documents which strictly extracted for the earliest data statistics.

Composing the Earliest Data Statistics
The appropriate documents used for this study have downloaded from the database of Scopus using two kinds of formats, namely Research Information System (RIS) and Comma Separated Values (CSV).Both RIS and CSV format composed by several prominent information of each documents, particularly abstract, keywords, bibliometric information and bibliographical information (Hudha et al., 2020).By utilizing Publish or Perish (PoP) software, these documents can be compiled in RIS format and directly can presented the earliest data statistics including information about citations, the authors, the title of document, the type of document, the source of document (by providing the journal or proceeding name), publication year, and also the publisher (Fahimnia et al., 2015;Setyaningsih et al., 2018).Moreover, the compiled documents also present about descriptive analysis overview namely number of authors per publication (NAP), the total citation (TC), number of citations per publication (NCP), the total publication (TP), number of citations per year (NCY), m-Index, h-Index, and g-Index (Hudha et al., 2020).Furthermore, the g-Index denoted the g-number as the highly cited documents with at least g2 citations, while the h-Index was computed las lh lnumber lof lpublications lwith lat lleast lh lcitation, land lthe lm-Index lwas lmeasured las h/g (Donthu et al., 2020).

RESULTS AND DISCUSSION
Performance Analysis 1) Publication-and-Citation-Related Metric The iprocess of selection idocuments has obtaining 761 appropriate documents regardless to its inclusion criteria.Furthermore, by using PoP software, the appearance of the publication-and-citation-related metric shown in Table 2.

Publication and Citation Metrics
Based on Table 2, it can be inferred that within 2011 to 2022, there were only 43 published articles which strictly related to the digital marketing research.In addition, these documents had been cited 366 times which means that the average citation succeed each year specified to be 30,55.It can be conclude that every single year during 2011 to 2022, these documents claimed already cited closely to 31 times.Moreover, the average of citations reached 7,81 per year which assumed that each document at least already cited 8 times roughly.The ratio of authors for each reached 3,19 and involving 140 authors.Based on this finding, it can be concluded that each document was authorized by at least 4 authors.Furthermore, the ih-index iof ithe idocument icollection iwas 11 which imeans ithat ithere iare 11 idocuments iwith iat ileast 11 icitations.iMeanwhile, ithe g-index iof the idocument icollection iwas i18 iwhich imeans ithat ithere iare i18 ihighly icited ipapers iwith iat ileast 324 icitations.This iimplies ithat ithe imindex iof ithe idocument icollection iwas istated ito ibe i0,611 which ipresents ithat ithe iratio ibetween ithe ih-index iand ig-index iis i11:18.iIn iaddition, iit iindicates ithat ithe ih-index iis ialways ilower ithan ithe ig-index (Donthu et al., 2020).

Science Mapping and Network Analysis
The analysis of Co-Word was performed to investigate the available or the upcoming topics related to the research field by concentrating in writing content of publishing documents (Donthu et al., 2021).In iaddition, ithe conducted ianalysis iwas utilized to provide the most appearing keywords regarded to the study of the digital marketing.Later, this analysis used in distributing the most appearing keywords in the recent period.At the first step, the analysis used the name of author as the ikeywords iwas utilize to provide the most appearing keywords by choosing ithe iminimum inumber iof iwords will emerge in 17 related keywords iin ifive iclusters as shown in ired, igreen, iblue, iyellow, iand ipurple.(See Figure 2).Besides, Table 3 showing five keywords in red cluster, four keywords in green cluster, three keywords in blue cluster, two keywords in both yellow and purple cluster.Moreover, the keyword "digital marketing" found as the most appearing keyword in blue cluster with total 18 times occurrences.It can be assumed that the keyword "digital marketing" is the most appearing keyword from all existing clusters in this analysis.Thus, this finding indicates that the keyword "digital marketing" appears in maximum of 18 different publishing documents.
Table 3. Hierarchical Clustering of Keywords Based on 36 keywords in five clusters, several keywords which interpreting the strategy used in the digital marketing such as "e-marketing" and "b2b marketing".It interprets that e-marketing is marketing strategy trends in the digital marketing.Some researchers also revealed that e-marketing as a part of the marketing strategies in sustaining the digital marketing (Krishen et al., 2021;Kumar et al., 2019).Mostly, some marketing strategies such as e-marketing and b2b marketing are usually used in the digital era.Afterwards, several interpreting keywords platform utilized in the digital marketing such as "social media" and "internet".Nowadays, generally, social media and internet have been utilized widely in the business field.Othman et al. (2021) described about social media as a well-known tool used to advertise the goods or services of the business.In addition, Saheb et al. (2021) argued that internet extremely supports the digital marketing in the business field.It proves that social media and internet extremely help the entrepreneur in conducting the digital marketing.
Furthermore, there was one keyword interpreting the business field using the digital marketing such as "tourism".It shows that the tourism is one of the business fields employing the digital marketing to advertise the tourism service.Donthu et al. (2021) also revealed that the digital marketing is implemented in the tourism business.In addition, there was one keyword interpreting the methodological research used in conducting the research related to the digital marketing such as "qualitative research".It reveals that qualitative research is the methodology trend employed in carrying out the research regarding the digital marketing.Furthermore, there was one keyword interpreting the accidental condition so that the digital marketing has to be applied such as "covid-19".It shows that mostly in the Covid-19 pandemic, the digital marketing is employed to advertise the goods or service to the consumers.
At the second step, the overlay visualization analysis used in distributing the most appearing keywords in the recent time.The analysis used the name of author as the keywords was utilize to provide the most appearing keywords by choosing the minimum number of words will emerge in 170 related keywords.Hence, the appearing keywords related to the digital marketing distribution presented in Figure 3. Figure 3 presents some keywords such as "digital marketing", "distribution", "customer satisfaction", and "circular economy" conclude as the most currently appearing keywords appearing in 2021.Some literatures also revealed that digital marketing and circular economy are the most recently emerging keywords related to the digital marketing (Donthu et al., 2021;Kumar et al., 2019).Krishen et al. (2021) also stated that distribution and customer satisfaction are the most recently emerging keywords regarding the digital marketing.These reports interpret that the keywords represent the most recently emerging keywords related to the digital marketing.

CONCLUSIONS AND RECOMMENDATIONS
The bibliometric analysis of this study presents several information which is related to the tendency and the development of research on the digital marketing.During the period of 2011 to 2022, there were 43 publications and 336 citations succeed regarding to the digital marketing although the quantity of the publications and citations development still relatively fluctuates.Hereinafter, mostly, some marketing strategies such as e-marketing and b2b marketing are usually used in the digital era.Nowadays, generally, social media and internet have been utilized widely in the business field.It proves that social media and internet extremely help the entrepreneur in conducting the digital marketing.In addition, tourism is one of the business fields employing the digital marketing to advertise the tourism service.Moreover, qualitative research is the methodology trend employed in carrying out the research regarding to the digital marketing.Mostly, in the Covid-19 pandemic, the huge spreading of digital marketing is performed to advertise the goods or service to the consumers.Furthermore, the keywords such as "digital marketing", "distribution", "customer satisfaction", and "circular economy" represent the most recently emerging keywords related to the digital marketing.

Figure 1 .
Figure 1.Publication and Citation Tendency of the Documents from 2011 Until 2022

Figure 2 .
Figure 2. Network Visualization of CO-Word Analysis.

Figure 3 .
Figure 3. Overlay Visualization of Co-word Analysis