The company that owns the site is not based in the US. I believe it's another country which is why they probably wouldn't send a 1099. The reason I think it's not self employment is because it really isn't. I'd consider it something I do once in a great while, not a job really. When I was trying to go that route and claim it as self employment it was asking me lots of questions as if I really was employed and again, it doesn't seem correct.
