I enjoy the opportunity to read the manuscript assigned to me titled Millennial Customer Loyalty in Online Shopping on Digital Platforms: A Perspective of Net Promoter Score. The topic is quite interesting. However, there are some issues that need to be addressed by the authors in order to increase the quality of this paper.

Studies on consumer loyalty to online shopping websites that were published in academic journals have been increasing in the last 10 years. In other words, “consumer loyalty to online shopping websitesâ€ is not a fresh or new topic, it is a bit obsolete and saturated. Therefore, the authors need to identify and explain clearly the research gap or the novelty this particular study has to offer to the journal readers. In this current version of manuscript, the research gap or novelty hasn’t been identified yet – so, for me, this is just another study about consumer loyalty in the digital context. There is nothing new or special (at all). Hence, for me, there is no reason (at all) why this paper should be published in this journal.

In the Introduction, the authors should explain why this topic is interesting and relevant for the journal readers. Why the journal readers should read another study on consumer loyalty in the digital context? Why it is important for the journal readers to understand NPS method? What is the relevance of the NPS method for them? If there is nothing special, important, or relevant in NPS for the journal readers, there is no reason why this paper should be published in any journal.

I also didn’t understand why it was necessary for the authors to use NPS method to measure loyalty. In the manuscript, the authors argued that “in digital platform business, consumers tend to be disloyal, and therefore the NPS can be used to measure the level of loyaltyâ€ – I have no clue the logic underlying that statement. In another paragraph in the same page, the authors also said that “consumer loyalty concept is a method of predicting attitudes and behaviourâ€ – what does it mean by “consumer loyalty is a methodâ€? Or “the concept is a methodâ€? I think that the quality of communication (the quality of English) shown by the authors is very poor. It is very inconvenient to read this manuscript because of the poor English.

In the Introduction (the last paragraph), the authors clearly stated that this study aimed to measure and map Millennial consumer loyalty. But, after reading the whole manuscript several times, I still couldn’t find the map, promised by the authors in the Introduction. And I don’t understand either, why this map is important for the journal readers? If there is no map, it means that this indicates that this study fails to achieve its objective. If this study fails to achieve its own objective, there is no reason to publish this manuscript in any journal.

Literature review presented by the authors is very shallow. For example, loyalty is a very established construct – it has been studied extensively so in developing a proper literature review, the authors need to review – not only re-tell – what has been done (and what hasn’t) in the current literature. However, literature review on loyalty presented in this manuscript is basically just copy-paste-and template/modify what other people were saying in their papers, there is no review at all. Doing literature review is definitely not enough by just putting definitions. The authors need to have a purpose. What the authors wrote about Digital Platform and NPS in this manuscript are also pointless. The quality of literature review presented here equals to the quality of a mediocre undergraduate thesis. It is very shallow – and very poor. If the authors showed lack of understanding on the existing literature in the field, it indicates that the authors lack of expertise and credibility in their own field. Why should a journal publish a manuscript from authors with low level of expertise and credibility?

In the Abstract, the authors stated that the aim of the study is to map consumer loyalty to online shopping websites. In the Introduction, the authors don’t develop any hypothesis. So, it will be logical and reasonable if I, or any other readers, think that the nature of this study is exploratory. However, in the Methods, the authors implied that this study is a confirmatory. But, it is not clear what this study wants to confirm. In the Result section, 
it seems that the authors did not use any statistical tools to confirm anything. So, for me, this study is confusing in its direction and the methodology it applied. If the authors showed lack of understanding in the basic methodology principles, it indicates that the authors lack of expertise and credibility in the research methodology. Why should a journal publish a manuscript from authors with low level of expertise and credibility?

In the Method, some important information is left unexplained. For example, this study asked the respondents to evaluate their loyalty to the shopping websites. However, it is not clear on what basis, the shopping website investigated here is defined. For example, it is very difficult to say Tiket.com, Traveloka.com, Grab, Gojek, or Gopay as shopping website/platform. Consumers don’t use Tiket.com for shopping – they use it if they want to purchase a ticket/voucher. Consumers don’t use Grab, Gojek, or Gopay when they want to do online shopping either. Therefore, the term shopping website/platform is unclearly defined. In my opinion, those websites/platforms listed in Figure 2 are not comparable. 

Moreover, if the respondents were asked to indicate their loyalty to the 13 websites/platforms (Bukalapak, Shopee, Tokopedia, Grab, Gojek, etc.) listed in Figure 2, it means that all the respondents must have adequate level of experience on purchasing/doing transaction on those websites/platforms. Otherwise, it is impossible for them to have any kind of loyalty. However, the criteria of the respondents used in this study seem to be too general. The authors wrote that the criteria used to select the respondents were “who used digital marketplace or online shopsâ€ and “having or never using a digital platform in the past yearâ€ (I don’t really know what it means – did the authors expect the respondents to have had an experience, or never had an experience? It can’t be both – why did the authors use the word “ORâ€?). So confusing. Is it another problem caused by a very poor English? How did the authors expect an individual who have never had an experience in online purchase could measure his/her loyalty to any website/platform?)

Another important information missing/unexplained in the manuscript is about data collection procedure. I am aware that the authors wrote that the questionnaire was distributed through several Millennials WhatsApp Group. What the earth is Millennials WhatsApp Group? How were the WAG selected? More importantly, the authors wrote in the manuscript that 500 respondents were selected for this study. if the authors distributed the questionnaire through blasting the questionnaire through several WAGs, how did technically the authors select the respondents? Again, this is the problem with a very poor English.

In addition, it is unclear either how the loyalty construct was measured. I know that NPS was used to measure loyalty. But, how? How was the loyalty construct operationalized? What items that the authors used to measure it? How did those items lead to the NPS numbers? How the score was calculated? What about the credibility and validity of the measurement items? Why were they not reported?  In the current version of the manuscript, the information about how NPS was operationalized was very limited. If the authors are given a chance to revise and resubmit this manuscript, please provide information about (1) how NPS was operationalized (2) how NPS was calculated, (3) how the NPS score was ensured in terms its credibility and validity – report it, (4) the items used to measure loyalty – all items that the respondents were asked to respond to – present the items in a table – and put the information about the Cronbach’s alpha and the validity measures in the same table. The information presented in the Methodology section is inaccurate, not valid, incomplete, and confusing – this again showed that the authors are lacking of understanding on basic methodological principles. Why should a journal publish a manuscript from authors with low level of expertise and credibility? 

Having read through the paper, a serious question came up to my mind. In the Introduction, the authors said that NPS is a method used to measure loyalty. However, in the Methodology, the authors implied that the respondents were asked to evaluate their satisfaction toward the shopping website/platform they used. This thought was strengthened by what the Table 2 presented. The Table 2 explained how respondents assessed their shopping experience – so, it should be about satisfaction/dissatisfaction – not about loyalty. Please clarify and address this issue. 

Another serious question for the authors is that Table 2, Table 3, and Figure 2 presented seem to illustrate how successful the shopping websites/platforms in providing consumers a satisfying shopping experience. This is a strong indication, because in p.8 (left side), the authors clearly grouped the websites/platforms into 3 categories. So, the results presented in the manuscript is a company map. This is inconsistent with the aim of this study stated earlier in the Abstract and the Introduction – to map consumer loyalty to the shopping website/platform. I have tried to find anything that can indicate the effort the authors have done to present a customer loyalty map, as promised, but I just couldn’t find it. So, is this study about consumer loyalty mapping or company mapping? Which one is correct? Please address this issue and make the paper consistent.

The authors need to explain about what this study has to contribute to the marketing literature and marketing practitioners. But, the authors didn’t explain anything about the research implications/contributions. This is somehow not surprising as the Introduction and Literature Review presented in this article are very weak. If, the authors couldn’t identify any contributions offered by this paper, there is no reason for the journal to publish the manuscript. 

This journal is accredited SINTA-2; therefore, in order to enhance the quality of the manuscript, the authors are expected to cite articles published in nationally accredited journals (SINTA 1-2-or 3) and/or articles published in reputable international journals. Please avoid citing from less reputable journals/sources. 

Regarding the poor English presented in this paper, it is strongly advised that the authors seek for professional help to fix the English.