Basically just like any other credit card except you have a certain amount of time to pay them back quickly to avoid the interest, I think it's like 6 months interest free. To use it, just buy something and select Bill Me Later and it'll pop up an application screen, then depending on your credit and income they'll approve you for a certain amount. be sure to buy something you normally intend to buy because you're still committed to buy whatever it is in case the bill me later doesn't aprove for any reason... Saying that, my credit was pretty poor when I applied and they approved me for a little over $300, which is plenty enough credit for me, then I just pay like $20 or so monthly or just pay it off at the end of the month... I really DON"T want to pay their interest rates so I always make sure I can pay off whatever I buy within 6 months or less, Right now I'm trying to get a higher limit and using this to boost my credit score so I've been buying stuff for around $100 then paying it down so it pays down in 6 months, then I'll buy something else for about the same price and pay it down the same way. but I've also used the whole amount then paid it off on payday too when I saw something I really wanted or that was going away before I got paid.