what made me check it out socialspark again was the new options for using twitter/facebook and cpc ads. you can use socialspark to advertise blogengage. Just set up an advertiser's profile. If you want to try it out before spending any ad money, just do a 'spark', it's free, and probably wont get a lot of responses because there is little reward for the blogger, but it should still bring some traffic (from bloggers) and a few links.
I am now receiving traffic from socialspark every day simply through my profile. The traffic has a low bounce rate, and high number of page views, so simply using the social side of it can be beneficial.