I think our next step is to limit the voting timeframe to two weeks. If we do not have at least 8 votes after two weeks we will refund 50% of the signup fee. That will motivate voters I am pretty sure.
I don't think you'll get rid of the problem, you're just getting a different problem. Now voters will vote to get compensated (or rather to not be punished for not voting), which contradicts the purpose of having peers review anything.
Step after that I think is to put together a team of 3-5 trusted community mods and somehow compensate them for reviewing contracts and voting according to some exchange determined guidelines.
This sounds much better. In fact, you can even split the listings in two groups; a high-volume asset like ASICMiner or AMC, which will impact the community far more in case of scams or defaults, would require more careful review, more votes, or something like that. 10BTC for listing, 5 goes to reviewers, 5 go to exchange.
Smaller assets like mine (market cap <1K
BTC for example) would require less of issuers. Listing fees could also be lower, but still require approval for example by the exchange itself (you or someone from your future team). 5BTC for listing, 2BTC goes to you, 3BTC goes to exchange.
Just examples, but a separation like this may make it easier to get listed for smaller issuers and earn more money for larger assets.
.b