Each seed had to meet the same study eligibility criteria required of other participants (described below). Seeds were given referral coupons with an expiration date four weeks from the date of dispersal. Each seed was allowed to recruit no more than three participants. This practice continued for all participants enrolled in the study. For FSW, six additional seeds were added to the study to sustain accrual, and for MSM eight additional seeds were added to the study when referrals began to slow.