The pimproll/domain parking that was in a thread a few weeks back has helped me with some of my interacial domains..
and what's cool is you can park.. but also put your own links on there.. so it helps with backlinks
And I'm getting a few SERP hits from how I filled out the metas and all that... I only got like 6 domains with them... and they were all nothing.. not even link farms.. and they got like 200 hits last pay period.. no sale yet.. but one PPS of $50.. pays for all their reg fees.. and I figure I'll squeak out 3-4 of those a year.. + the back link building..
So I figure SEO help with the backlinks... + maybe $150-300 per year.... on domains that WERE doing nothing...
So on your domains that are niche, but aren't something you're inspired to build... do this...
http://links.pimproll.com/?s=pimproll&r=pimp30524