We're actually using the most popular SE to promote our website, however we're constantly looking at new possibilities to expand our traffic (and conversion) volumne.
The problem I'm facing is that the alternative I've tried are too expensive and low quality, not so many platforms have the quality of adwords or bing. So we're looking at cheaper options like remnant advertising. I understand that the base of this type of advertising is re-sell the unsold ad space at a discounted price. But, how can I buy those spaces? What platform are using this kind of advertising? Does Google have a similar option?
If done right it could be a great value for both. It all depends on the type of remnant advertising that you buy and the messaging of your ads.
For direct response campaigns, remnant inventory could be an amazing source of traffic since would would be paying out a low CPM/CPC for traffic from premium sites. The key here is to keep optimizing your placements and creatives. AdBrite actually lets you choose the sites that your traffic comes from, so you would be able to play around with placements and see which ones generate the highest ROI.
As far as branding goes, remnant advertising is an excellent source as well. Once again though, you'll need to be smart about it. A lot of remnant inventory vendor will sell you RON traffic, where they will mix in traffic from top tier sites with traffic from not so stellar sites. The key here is to be vigilant. Find out what the ratio of sites is, demand a site list, and target if you can.
Thanks a lot! It seems that best choice are platforms which let you decide your placements. I'm actually looking at AdBrite, Right Media Exchange and Doubleclick. I hope to make the most of them. Thanks for your help!