Table 3.

Summary of recruitment strategy advantages and corresponding disadvantages (where applicable) according to recruiters’ perspective

Advantages	Disadvantages
In-Person
Easy to build rapport and provide a sense of legitimacy to the project	Labor intensive
Able to provide immediate specific details regarding the project	Unable to restrict contact to the target population
	Multiple visits to the same location (e.g., community center) led to saturation
Social-Media Based Tools (Facebook, Craigslist, mobile apps)
Immediate dispersion of study information to many individuals simultaneously	Difficult to build rapport with potential participants
Able to use filters to restrict contact to target populations (e.g., sexual preference, self-reported HIV status, gender)	Users can accuse study profile of being “fake” or messages as solicitation/spam
Can be done remotely from any location	Profiles associated with the study are prone to getting suspended/banned
No fees for basic services	Extra costs associated with upgrading app to view/access users in a larger geographic catchment
Easily able to track individuals who have been previously contacted using certain platforms (e.g., Grindr, Adam4Adam)	Other platforms, specifically Craigslist, unable to determine if users had already been contacted, resulting in one user expressing frustration. Recruiters changed strategy to update only publicly displayed posts containing study-related content
Individuals are contacted privately, allowing for greater confidentiality regarding participation
The GSN have messaging systems that are based on phone location and will allow messages to other users within the vicinity based on location of user	Requires changing location to avoid messaging the same individuals in one general area
Referrals from other research studies
Individuals already interested in participating in research	Risk of homogenizing sample
Many have some experience participating in research studies previously, familiar with similar protocols	Risk of recruiting individuals who are trying to qualify regardless of eligibility criteria
Print (Palm Cards, Flyers)
Visually appealing way of promoting study details concisely	Higher cost for color/laminated option, extra time required for design considerations
Provides study contact information for later use	Some people may not want to carry research study information on his/her person

Note. GSN= geo-social networking