I have an idea of starting a website where customers can rent things like books, clothes, etc. but I just don't how I should go about making sure the customers will return them, I make a profit, etc. An idea is to charge them the full price of the product, and then when they return the item they get refunded 90%, etc.. What do you guys think?
You're talking about starting a company not just a web site. If you are looking to rent or sell things like "books" or "clothing" those are two VERY different and VERY large markets full of different niches. I'd imagine before you even take the next step you have a multi million dollar budget to afford the inventory? If you don't then you are worrying about nonsense.... lol who cares if they return it if you don't have the means to stock it to rent it in the first place........
This is actually a very good concept which reduces environmental burden and also helps in optimal use of available resources. This is not a new concept and there are quite a few companies doing this successfully. What I think you can do is.. Verify ID proof and Address proof. Take 30% as refundable deposit. Impose fine for late returns. I believe the above three things would be sufficient to prevent 90% of the scammers.
You can certainly set up a rental business using Yo-Rent platform. There is a great app that would allow for booking methods.