While SidelineSwap takes a fee from each sale, SidelineSwap will never require you to purchase any kind of gift card to authenticate your account or permit you to sell your gear. There is no such thing as needing to get set up for "instant payment" on SidelineSwap nor are there "selling limits" or a need for an "unlimited limit". As a reminder on how to sell on SidelineSwap, read here: How to Sell.
SidelineSwap will only ever send emails from one of the below email addresses:
If you or someone you're speaking with claims to have gotten an email from SidelineSwap, but the email address is not included in the above list, this is a scam. As a reminder, keep all communication and transactions on SidelineSwap. This is the most effective way to ensure you, your gear, and your money is fully protected.