Save yourself and use another app or website. This company is a joke! They start off by giving you the impression of good exceptions, then totally low-ball you when you actually go to sell. The world would be a better place if there weren't scam companies like this. They have no ethics when to comes to their customers!
Plus, they tell me they can't link my PayPal because it is not "verified"... which is very very very odd and suspect since I literally just used my PayPal to make a purchase this morning, and my PayPal account has been in good standing for over 10 years. Save yourself the aggravation and sell you books to a legit company!
Lastly, you can totally tell they are not legit due to the fact that on their website they boast a 4.5 star rating - but if you look ANYWHERE online else they only get a rating of 1.5 - 2 stars. I guess honesty and integrity are not a part of their business culture.