See Aaron Wall's Linkharvester (Yahoo backlinks tool). I just took a look at it for a site that is in one of my coop ads but not actually hosting the ads (i.e., not a coop member site in itself yet). There were a large number of backlinks showing in the "Unique Commerical Domains (*.com, *.net, etc) with Unique C Block Addresses" section that are very clearly from the Coop -- with zero probability that they came from any other source.
Thats right, even I was growing naturally in Yahoo day by day, with co-op I got another boost. The same with MSN.
I'm new to the co-op but definetly seeing results in yahoo and msn. Not much with google but of course google doesn't show a lot of my links
I think that might explain why yahoo thinks my site is of some interest. I dont have much wieght, but yahoo thinks one post on my forum is worth ranking pretty high for searches on "gumball 3000 2006" and other strange searches to do with the gumball rally. cool.
Not sure if everyone is seeing this. But I am finding that Yahoo is "sandboxing" some of my sites after I placed a large amount of weight (>10k) toward a site despite spreading the weight to different pages and different anchor text. Probably hit some kind of filter. I get a good result for a couple of weeks and then all of sudden dissappear.
What exactly do you mean by dissappear. Do you mean your rankings have gone down or are your rankings not be found in the first 1000 results. Also would be interesting to see if you have recovered for any of them. I myself had the same thing happen to me, but in this case my site is not ranking for anything at all anymore. Not even the domain name > zero traffic from yahoo.....