Any fees removed from your profits as a seller are from PayPal, not from I Shop JW.
Paypal is a service that allows buyers and sellers to exchange money without giving out any personal information. If you have a paypal account you can securely send and receive payments from a credit card or your banking account to anyone, worldwide.
Buyers can purchase from Paypal even if they don’t have a paypal account by using their credit card information to make the purchase. (However if using a paypal.me link, payments can only be sent if the person has an existing paypal account.)
Because Paypal makes purchases between people so easy, they do charge some service fees for business or commercial use. It is free to send money or goods to family or friends, but for purchases of goods or services paypal will charge the seller 2.9% + $0.30 per sale. (As of April 19th, 2018)
You can find more information about Paypal’s selling and buying fees on their official website here: https://www.paypal.com/en/webapps/mpp/paypal-fees
Most marketplace websites charge you a fee for listing your items and selling through their website & then if they process your payments through Paypal, Paypal also takes a cut -so you could potentially be getting double the fees!
IshopJW is free to use and does not charge listing or selling fees, so if you sell directly through Paypal, Paypal fees would be the only cost to you as a seller.