NEW YORK (AdAge.com) — Publishers fighting hard to squeeze every last dollar out of their onlAine-ad inventories have turned to a variety of players to help them make the most of that space. But in doing so, they’ve let a lot of hands into the cookie jar and may find that the increasing complexity — and the crumbs they’re left with — aren’t worth the effort.

It’s not just publishers turning to middlemen but advertisers, too, hoping to boost targeting and effectiveness of their buys. The space between advertiser and publisher has become jam-packed over the last decade, with literally hundreds of ad networks, data companies, yield managers, ad servers and exchanges all purporting to serve advertisers or publishers in some unique way; but all have their own business models that may or may not be adding value to either. And they’re all dipping into the display-ad revenue stream.

In a not-atypical scenario, a publisher may only receive $1 of a $5 cost-per-thousand media buy once all the middlemen have taken their tithes. Where does the rest go? According to an estimate from Tolman Geffs, co-president of investment bank Jordan Edmiston, it gets divided like this: The agency ($.75), ad network ($2), data provider ($0.75), ad exchange ($0.25) and the ad server ($0.25). READ MORE