Facebook for recruiting Spanish- and English-speaking smokers.

•Recruitment of English-speakers and Spanish-speakers smokers through Facebook is feasible.•Cost-per-consent was higher for Spanish-speakers smokers than for English speakers•Ads for U.S. Facebook users performed better than for San Francisco users.•Spanish-speakers engaged more with the Ads than English-speakers.•A self-efficacy ad performed better than the fear-appeal ad.