(A-H) List of Legit Ad Networks and Affiliate Programs

Common acronyms of online advertising:

• CPM - cost is calculated by impression. You are paid when an ad is shown.
• CPC - cost of ads are calculated based on number of clicks. You are paid when someoneclicks on an ad.
• CPA - cost per action. You are paid when the visitor does something -- for example, filling out a form or buying a product.

24/7 Real Media

24/7 Real Media offers standard graphic ad units with CPM and CPC campaigns. The account managers are really responsive, but their interface is horrible. Going through the advertisers and checking your earnings is a really convoluted and slow process.

ad pepper

Ad pepper can provide exclusive or non-exclusive representation for your ad inventory. They offer many types of CPM ads including graphic, contextual, and integrated text links.

AdBrite

AdBrite offers CPC, CPA, and CPM in a variety of formats including text ads, inline ads, banners, video, full page ads, ads in photos. You can set your own price and run ads from another ad network if AdBrite can't supply an advertiser at your asking price.

AdDynamyx

AdDynamyx offers CPM and CPC graphic ads featuring Fortune 500 Advertisers. They serve standard ad units as well as various types of pop unders and floating ads.

AdEngage

AdEngage shows targeted text ads (they now have PhoText Ads which includes a small image with the text). They sell ads as a weekly sponsorship package with your ad space priced by week. You set your own rate, but advertisers can see your stats, so they can evaluate your cost per click anyway. If your inventory isn't purchased, CPC ads are displayed.

Adfish

Adfish is a small affiliate network and only offers CPA ads. They don't have an overwhelming number of advertisers, so it's a good place for a beginner to learn the ropes of affiliate marketing.

adknowledge

adknowledge offers targeted CPC graphic and text ads, as well as email and search campaigns. They use behavioral targeting to serve the most relevant ads, and boast having over 50,000 advertisers vying for your ad space.

AdOn Network

AdOn Network offers CPM (they call it CPV--cost per view--for some reason) text and graphic ads. You can't sign up online--you will need to shoot them an email and a representative will contact you.

ADSDAQ

ADSDAQ runs text and graphical CPM ads and allows you to set your CPM rate. They also use performance stats to serve the highest performing ads first, which benefits both the advertiser and publisher.

Adsmart

Adsmart serves the U.S. and U.K. extensively, requiring a minimum of either 70% USA traffic or 70% UK traffic, and 100,000 monthly page views. They offer CPM and CPC campaigns and pays out 55% of net sales revenue.

adsonar

adsonar claims to "raise the relevancy bar" by delivery content-targeted ads better than other networks. Advertisers bid for placement and run if it meets your minimum bid requirement.

Adtegrity

Adtegrity does not accept ads that do not meet their ad quality standards, such as Adult material, excessively flash ads, or "ads simply in bad taste." They also don't run PSA's or default ads that has no revenue potential. They offer CPM and CPC ads and guarantee 100% sellout of your inventory. They require 500,000 page views/month and 50% USA traffic.

AdToll

AdToll allows you to set your own price and pays 75% commission. They offer CPM and CPC ads in all the standard ad units, including Video Ads as well as a new ad unit called a Peel Away Ad where an ad is hidden under your page and is activated upon a mouseover by a user.

Advertising.com

Advertising.com claims to be the largest online advertising network. They offer rev-share, CPA, and CPM pricing options that you can set the minimum for. You need a healthy two million impressions per month to join (their affiliate program does not have a minimum traffic requirement).

Amazon Associates

Amazon Associates is one of the most popular affiliate programs because it is easy to sign up and implement. Amazon offers many different types of ad units to fit your needs (automated ads or publisher generated links for specific products). If a visitor clicks on your link and actually purchases something from Amazon, you get a percentage of the sale.

AzoogleAds

AzoogleAds is a large affiliate network serving CPA ads from Fortune 1000 and Fortune 500 companies. They offer solutions for search, web and email campaigns.

Bannerconnect

Bannerconnect specializes in both US and EU markets and offer 100% fill rate for worldwide traffic. If you get substantial traffic around the world, they can provide the inventory for those page views. They offer CPM, CPC and CPA ads.

BannerSpace

BannerSpace offers different levels of representation depending on your traffic and exclusivity. They can take over your entire sales department by putting a team on your site and managing your entire inventory. They can also work with your existing sales team to fill remnant inventory. For small to mid-sized sites (less than 20,000 daily page views), they work like most ad networks, supplying CPM/CPC ads to fill up your inventory.

BardozoMedia

BardozoMedia provides "targeted and optimized" graphic ads to publishers at at a net share of 70%. They cover the U.S., Canada, and Europe.

BidVertiser

BidVertiser serves CPC text ads on your site as well as your feed. Rates are determined by advertisers who bid on your ad space.

BlogAds

BlogAds specializes in selling advertisement on blogs. Their ad unit combines images with mult-linked text. You can set your own prices (they take 30%) and write your own blog description to sell your ad space. You need to be invited by a current blog member in order to join.

lue FN

Blue FN is an ad network that features financial services advertisers. All their ads are either CPC or CPA and your site must contain finance-related content.

Bravenet Media

Bravenet Media supports on-site advertising programs, email sponsorships, co-registration forms, and other specialty media programs. They only accepts sites with a minimum of 1 million ad views per month.

Burst Media

Burst Media has two different programs in their network. Burst Network focuses on Target Advertising sold on a CPM basis. Non-targeted Advertising campaigns are sold at lower CPMs and include CPC ads to fill up inventory. They keep 50% of the ad revenue but offer better rates for publishers who agree to one year or three years exclusivity. Burst Direct is the other program they offer that run performance-driven campaigns. They take a much smaller cut (35%), but the revenue potential is probably more uncertain.

Chitika

Chitika offers one-of-a-kind ad products that provides powerful and integrated promotions. They are all CPA ads for products, so is a good network to use if your site is related to shopping or has a good tie in with products. Chitika offers a wide variety of categories and ad units to choose from, so you have more control over the type of products to feature instead of depending on keywords to be picked up by their ad server.

ClickBank

ClickBank is an affiliate network with over 10,000 products available. Commissions range from 1% to 75% with a minimum commission for a single sale at $0.25 and the maximum at $100.

Clickbooth

Clickbooth is an affiliate network that has been around for more than a few years. They test all their offers to ensure income potential and gives weekly payouts to top publishers. They also donate a portion of their revenue to charitable causes.

Clicksor

Clicksor offers both inline text ads as well as targeted text and graphic ads in various sizes. You can choose from CPC, CPM, or CPV ads and earn up to 60% of the ad revenue share. Their system will evaluate the content on your page and serve relevant, contextual ads.

clixGalore

clixGalore is an affiliate network offering text and graphic ads to promote merchants and earn commission.

Commission Junction

Commission Junction is a popular affiliate network with a huge selection of advertisers. All their ads are CPA or CPL and are offered in different ad units. You do have to get approval from each advertiser separately in order to get the ad code. This adds a cumbersome step when using their program.

Commission Soup

Commission Soup is another affiliate network that offers pay per performance programs exclusively. Similar to Commission Junction, you need to apply to each advertiser's program separately. View their client list

OPEAC

COPEAC offers affiliates top payouts and quick payments using an optimization system that drives traffic to the strongest performing landing pages, increasing conversion rates. Their team will also work with you to create designs that optimize exposure for immediate results.

CPA Empire

CPA Empire focuses on providing a high level of affiliate support to help your campaigns do well. Their initiatives include banner ads, text ads, search marketing, and email promotions. They have over 700 live campaigns.

CrispAds

CrispAds caters to blogs and serves contextual graphic and text ads based on the keywords and advertisers you select. Most are CPC ads unless ads are purchased as a monthly sponsorship at the rate you set. Unlike most networks that have a minimum payout of $25-$100, their minimum is set at a low $5.

CX Digital Media

CX Digital Media is an affiliate network offering CPA campaigns from Fortune 1000 clients. Benefits include twice monthly payments and a rewards program where affiliates can claim prizes based on the money earned. They require 5,000 impressions per month to join.

Direct Media Exchange

Direct Media Exchange auctions impressions to the highest-paying ad network. CPM campaigns are served (with CPC/CPA ads optional) and their marketplace includes many networks such as Adtegrity, BannerConnect, CPX Interactive, Kitara Media, Revenue Science, Rydium, and Vizi Direct. You can tap in to all of these ad networks at the same time and get the highest rate among them.

FeedBurner

FeedBurner is a popular network that offers advertising for your feed as well as your site. Their site ads include Google Adsense to get the most inventory fill for your space. Even though FeedBurner does not have a minimum feed count to serve ads, advertisers are unlikely to purchase feeds with low numbers.

Flux Advertising

Flux Advertising is an affiliate network running performance based ads. An account manager will be assigned to you to help guide you to the promotions and offers best suited for your site. This is optimal for those who need more personal attention to get started. They also offer a bonus rewards program where you can claim prizes based on your earnings.

Google Adsense

Google Adsense is the most popular and widely used contextual advertising network. They serve CPC ads (image or text) based on the content on your page. Advertisers bid on keywords so the CPC rate varies from one ad to another.

HerAgency

HerAgency does not work like a typical ad network where ads are dispersed to hundreds of sites at any given time with little discretion. They make buys and create campaigns for sites individually as well as a package of quality women-oriented sites. Their cut ranges from 35-50%, depending on your site's traffic, and the requirement to join is 200,000 monthly page views (and of course, a primarily female audience).
Reference: http://onlinebusiness.about.com/od/affiliatemarketing/tp/online-advertising-networks.04.htm