Almost all basicly allow for unlimited use, but no redistribution. Just like software, you can use it any way you see fit, but you can't give away or sell the item itself. A very few items require a further purchase or permission for commerical use, there was talk about having those items clearly marked that way on the sale page, I don't know if that was ever done, though. I think it should be, though, you shouldn't have to contact the vendor to find that out... There is also a basic Marketplace licence that applys to all, you can find it somewhere in the store section.