This ( openx.com/) is both an open source ad serving platform, and a service that lets you manage and sell advertising inventory. I've tried to use it a few times, and ended up confused, so I've dropped it. It's a very comprehensive system but rather confusing to use.
The OpenX Market is a marketplace where advertisers can browse for places to post their advertisements. You probably want to list yourself there.
This ( http://www.oiopublisher.com/) is a fairly simple to use, straightforward, ad managing application that supports direct sales of advertisements. You install this on your own server and set up your own pricing etc. It supports banner ads and text ads, and can even mimic google adsense if you like.
There is a marketplace for OIOPublisher sites to list their ad inventory for sale.
It costs $47 to buy a license that serves an unlimited number of domains.
This ( igloohq.com/) is a hosted service that is billed as allowing: Sell advertising directly; Low administration; Easy set up; Build your advertiser space
It integrates directly with the website via code snippets - they do not provide simplified integrations for specific website platforms.
Advertisers can directly buy ads off your website. The advertiser has a self-service experience.
You can directly contact advertisers via the provided contact list.
There are subscription fees for every service level - and there is not a free service level.
This ( adspeed.com) is a hosted service that is billed as "combining the latest ad serving technologies with advanced web analytics to maximize your advertising revenue. AdSpeed is an independent ad server and ad manager. You enter ads from your advertisers with targeting criteria into our system. We serve ads, track and report real-time statistics about ad impressions, clicks, revenue, and conversions. You manage your ad inventory through our user-friendly interface."
Comprehensive set of features
This ( trafficspaces.com/) is a hosted service that's billed as "advertising made easy".
Advertisers sign up through a self-service storefront.
There is a free service level, and several paid levels with higher levels of service. Traffic Spaces does not take a commission out of your sales, so your only cost is the monthly fees.
At a high enough service level you can put enough branding on the self service ad sales area to make it look part of your site. They even let you connect it to your own domain, and create your own ad network (whatever that means).
Other options not yet evaluated
- Author Advertising Plugin
- WhyDoWork AdSense Plugin
- Advertising Manager
- Advertisement Management
Google Ad Manager a.k.a. doubleclick for Google
Doubleclick ( google.com/doubleclick/) is an early dot-com success which Google snarfed up a long time ago. The typical webmaster will want to click directly to the Publishers section, but they also provide services for advertising agencies and others who want to place advertising.
The system is described as a Comprehensive ad serving technology that enables you to seamlessly manage and accelerate your digital ad operations across web, mobile, and video. It Leverage Google's advanced machine learning algorithms to match ads to the users most likely to respond and deliver even greater campaign lift for advertisers.
The key thing to recognize is that there are no prices on the website, instead you're instructed to contact the sales team. This is a broad hint that you'd better be rich already because there will be fees involved.
How To Setup Google Ad Manager on Your Blog/Website - looks like good instruction on using it.