Dear Dr. Grant,

I was interested to read the paper ‘Behavioural tracking and profiling studies involving objective data derived from online operators: A review of the evidence’ by Delfabbro et al. (2023). As someone who has been publishing papers for over a decade using data provided by the gambling industry, I was pleased to see that 20 studies that I co-authored were among the 58 outputs identified in the review (56 peer-reviewed papers and two “major reports” [p.4]). However, many studies were missing from the review.

The paper’s aim was to systematically review what is “currently known from 15 years of studies involving the analysis of objective behavioural data sourced from gambling operators” (p. 3) up until December 2022. The authors also noted that for inclusion in the review, the study “had to involve objective online behavioural data in at least some part of the research rather than self-reported attitudes or knowledge relating to online gambling” (p.4). The review also noted that the search for studies had used the Scopus database and that “further publications were identified through some earlier published reviews; through inspection of secondary sources cited in the most recent (2022) papers” (p.4).

Given that the aims of the study were clear and that the only inclusion criterion was that the study had to include online behavioral tracking data, I was somewhat surprised that 14 studies that I co-authored and were published before December 2022 were not in the review (i.e., Auer & Griffiths, 2014, 2015a, 2018, 2020, 2022a, 2022b; Auer et al., 2018, 2019, 2023 [this paper was first published online on May 29, 2020]; Chagas et al., 2022; Hopfgartner et al., 2021; Leino et al., 2015, 2017; Sagoe et al., 2018). Three of these studies admittedly included video lottery terminal (VLT) player card data provided by the Norwegian gambling operator Norsk Tipping (Leino et al., 2015, 2017; Sagoe et al., 2018), but all three studies arguably fitted the remit of the review and Norsk Tipping is an online (as well as offline) gambling operator. However, the other 11 studies all clearly fitted the inclusion criterion. Moreover, most of these studies had been cited in the other papers that were included in the review (especially those that I co-authored).

It should also be noted that one of the studies that appears to be missing (i.e., Auer & Griffiths, 2015a) may have been in the review but was mis-referenced (i.e., Auer & Griffiths, 2015b) although both of these papers contained behavioral tracking data and both should have been included based on the review’s remit.

It was also unclear why the two “major reports” in the gray literature by Price-Waterhouse Coopers (2017) and Forrest and McHale (2022) were included and not others. Both these studies were published by GambleAware but other major reports by GambleAware using behavioral tracking data have been published (such as those by the Behavioural Insights Team [2021a, 2021b]) but none of these were cited.