Direct messaging via text messages (texts) and emails is a widely used method to advertise sports and race-betting offers. However, they have attracted little research, as this advertising is not in the public domain. This study aimed to determine whether betting expenditure is related to receiving direct wagering messages, and the specific inducements they promote. We hypothesized that receiving direct messages, particularly texts, would be related to betting expenditure within 24 hr.In this ecological momentary assessment study, regular sports (n = 98) and race (n = 104) bettors from Australia completed short daily surveys over 1 week that captured exposure to direct messages, betting behavior in the previous 24 hr, and betting intention for the next 24 hr. Respondents were asked to forward any texts and emails received to the researchers, who coded them for inducement content.Longitudinal analyses found that receiving emails was positively associated with betting intention, whereas texts were positively associated with higher likelihood of betting and betting expenditure. These effects persisted when controlling for problem gambling status and signature betting events. Refund stake and bonus odds inducements were positively associated with likelihood of race betting (although not in multivariate models), as were bonus winnings inducements for sports betting.Direct messages, particularly texts, are powerful marketing tools, encouraging a nearly immediate, and arguably impulsive, betting response, which may increase gambling-related problems. Overseeing this private form of advertising presents challenges to regulators, and to public health efforts that aim to reduce gambling harm.