Recruiting a representative sample of pregnant smokers for descriptive or intervention studies is challenging . Pregnant smokers may be reluctant to disclose smoking status due to social stigma (particularly in a clinical setting), making self-reported smoking status an error-prone measure. Furthermore, biologically confirmed smoking status (eg, cotinine testing) is expensive . While in-person recruiting in prenatal care settings has been the norm in research to date, new opportunities have emerged to leverage social media and crowdsourcing to more easily recruit pregnant smokers as research subjects. Crowdsourcing platforms are Web-based marketplaces that allow researchers to post research tasks (such as survey completion) that interested subjects can complete for pay. Crowdsourcing offers an easy way to quickly recruit a large sample of study respondents that is more diverse (geographically and sociodemographically) than the typical college student young adult sample or an in-clinic patient sample . Crowdsourcing platforms such as Amazon’s Mechanical Turk (mTurk), Soapbox Sample, and Qualtrics Panel Data draw a broad demographic of workers that can meet even very specific and targeted inclusion criteria . Compensation for research task completion through crowdsourcing platforms is typically lower than in-person research participation with substantially lower research staffing costs, making crowdsourcing an appealing option for maximizing limited research budgets . To date, Amazon’s mTurk has been the largest and best-known crowdsourcing platform due to low costs, flexibility, anonymity of workers, and, for researchers, the demographic diversity of the worker pool . Social media is another online recruitment platform that extends researchers’ reach beyond the limitations of in-person recruitment. About 74% of the 2015 US population had Internet access and more than half of that population used at least one form of social media . Social media allows for precise targeting of messages (including invitations to participate in research) to specific demographic profiles or interests. For example, the social media platform Reddit comprises many smaller interest groups called “subreddits” where members view other members’ posts, news, images, and media links. Advertisers, including researchers, can place ads on specific subreddits, such as a pregnancy or smoking cessation subreddit, to reach the desired target audience.