Should I Keep Submitting?

Got another piece of mail about another big writing prize, but if I think it's attractive scads of other people do too. Haven't actually won a prize since junior college. I've been trying cause "You never know!" and it makes me feel like a real writer, sometimes, and I do have the money and stuff. But maybe I do know.
Treating submitting like my phone work hasn't helped because different markets want different things.