The problem I see with infolinks:
Took about a week on each blog for the keywords to finally have something decent that had to do with the keywords.
But still, keywords will off and on have non-related ads.
So that tends to turn people off to hover over a keyword like "swimming pools" and see some site on the little pop up that is about shoes.
And I think they do pay terrible, so their advertisers must not be high paying either.
Another problem with infolinks and similar in-text ad systems is they can be quite annoying for the visitors. Given how little they pay that doesn't seem to be worth it. I'm doing a test run for a while on one of my sites (albeit not updated for a while), and I agree it's very low. I make about a dollar a month.
I've had very good results with Infolinks, unlike Kontera.
I've yet to test VibrantMedia in some of my automotive sites.
When you guys mention content sites you're talking about what kind of traffic? (and source of traffic)
If it's any help, I have heard through a few different sources, that Facebook is working on a competitor to Google AdSense. I don't know the exact timing, but I would expect it sooner than later.
Infolinks did better than Kontera for me for 6 mos, then the two reversed course late last year and I went mostly with Kontera from then on. Blogs with less than 1,000 uniques a day don't really see much action, however, the power in this type of ad network seems to be that it is additional revenue on top of Adsense when run in parallel on sites with large volumes of visitors. I do not run Kontera or Infolinks on blogs that do ok or better on affiliate sales (this is ill-defined by myself as enough affiliate sales to drive me to check the stats each month of the offer(s) ).
This past spring saw Kontera bring in approx 6% addnl income for me over adsense over more than 3 million uniques for data points. Believe Will has stated publicly on here sometime in the past year or so he sees or saw 10% on one of the three mentioned above (maybe Vibrant media?).
This is David, from Kontera.
If you want to respond with your URL or Email (or email me at email@example.com), I can look into your account and see what we can do.
Look forward to hearing from you.
Hey, this is Tammy from Infolinks. Go ahead and give our In-Text ads a try. We guarantee the highest payouts in the industry and our team can help you optimize your site for the best monetization. You can also control how many ads appear per page as well as how they appear. Shoot us an email to firstname.lastname@example.org to learn more.