I do some trading on Bter.com and the popular coins there do big volumes (hundreds of BTC).
They have a Voting Tab and DigiByte is listed, but currently we're down at position 120 out of 240 coins. You get 5000 "trading points" for every BTC of trade you do, and a vote costs 100 points.
If you do want to signup please use my referral link below. Using it will get you 10% discount off your trading fees for 6 months and I can use the referral bonus to put more votes towards DGB too.
https://bter.com/signup/223434
They also mention that if you get enough BTR (trading points) then you can get 1 to 10 free votes per hour too. (I think you need over 1000 BTR points for that to kick in)
We can also try asking them on Twitter, apparently they have added popular coins through Twitter requests before.
https://twitter.com/btercom
Oh, and just as it's happened to me again (and I'm not sure why), but everytime I try to Reply to the thread with it's current Subject, I get a warning that the Subject is too long (over 80 characters) and I have to delete some of it.