The short answer is, No. Never.
All research participants that are recruited on the platform must be paid through the platform. Respondent pays research participants who complete a project via PayPal.
There are several reasons why payments must be made via the Respondent platform:
It protects researchers and respondents in the event of a payment dispute.
Being paid is confirmation that the research participant successfully completed their obligations; this improves their reputation on the platform.
Cash (in the form of PayPal transactions) is the best motivator of participation - gift cards and vouchers are proven to negatively impact interest in research studies.
While it's tempting to offer Participants gift cards voucher incentives or the offer to enter the Participant in a competition, well, it goes against Respondent's Terms of Service, and that can get you removed from the platform.
Please use PayPal for all of your incentive payments. It keeps all of us organized. 🗄