I don`t think this is a really great domain. If this comes in Google instant, it dose not mean its good. You should have checked its Global monthly searches and some other relevant data.
This keyword only gets 320 Global monthly searches, which is very low.
I don`t want to make you feel bad or just discourage you but just want you to know that you should check some other things too then only Google instant. It is their just to help in search and not to provide any analytical data.
Their is still a good news for you.
"promote forum" gets 1,900 Global monthly searches, which is not that great but better then full length domain. So just need to do your seo with this keyword and you will get much more benefit then promote your forum. 🙂
meSingh has pointed out the SEO issues but as a domain for people to remember it's a great one. You could set up a webmaster blog or forum or directory on it. I'd value it at around 30$