Stack Influence
Mostly a gifting marketplace: free product for posts, with paid collaborations offered occasionally.
What it pays
Mostly gifted collabs: free product in exchange for posts, with cash pay offered only on some campaigns. Stack Influence's own site says $17.4M+ has been paid to its influencers to date.
How and when you're paid
PayPal. A PayPal email is required to join, since it's the only method listed for sending any cash payment.
Who can join
At least 200 followers on Instagram; original content required. US-based for most campaigns, per its creator FAQ.