Just a little advice, Netbooks are the wrong choice. Unless you're using it for small things like email. Other then that, they're slow, low-medium performance laptops that aren't worth it, especially since it's only 30 bucks. . Go for a laptop cheapest being around 300+.
Oh and to answer your question. Yes, they will pull some sort of contract on you. You pay monthly for internet service and downloads ( 500mb, 1 gig, 5 gig, etc)