I love Miva, and lots of the C-level folks there. Really good people.
Traffic is 2nd tier and they don't try and pretend like it isn't. Same rules apply for all 2nd tier. You have to buy in LOTS of volume and keep your fingers crossed. Sometimes it works, other times it doesn't. It's a coin flip everytime.
Ohhh you said Publisher. Shit, well I think the same rules apply for advertisers and publishers in the 2nd tier. You need to get lots of volume in order to make bank, although their rules and targeted niches are a lot more lax than those of Tier 1.