Once you have an offer to promote and a banner created, you need to start looking for places to advertise. You have two options when going into ad networks: Some networks allow you to specify the sites you want to advertise on, while other networks only allow you to specify categories, and only broker so–‐called “remnant traffic” from other networks.
Adbrite Exposed You may or may not have heard of Adbrite, but it’s a platform that allows you to find websites to place your banner ads on, and also allows you to outbid competitors for the same ad space. Adbrite allows you to use either PPC (Pay Per Click) or CPM (Cost Per Thousand). PPC, however, is for “network wide” ad placements and can get you 
a lot of untargeted (and non–‐converting) clicks at your expense, while CPM allows you to target individual sites. Make sure you choose the individual site–‐targeting option, or you will end up with traffic that doesn’t convert, and once you find a site you are interested in advertising on take a look at the site’s demographics using Quantcast.com to give you an idea of what kinds of offers you are promoting might be a good match (not many people know you can get the kind of extremely cheap Adbrite traffic you can find if you look for individual sites, and if you combine that strategy with market research and demographic targeting, you will be far ahead of most other advertisers). For a daily budget, I always set my budget at $100, just to “test the waters” and see whether a campaign is worth putting more money into.
BuySellAds With BuySellAds, you can pay a flat monthly rate rather than by CPM, so you could conceivably get 22 million impressions for just $300. They also allow you to pay with PayPal, which makes it very convenient. Each site listed gives you the number of impressions, the site’s traffic rank, eCPM (estimated cost per thousand), and the monthly price for the ad placement. Each site specifies its own accepted banner sizes, and if none of the banners supplied by the CPA network are a match you can either use one of the banner–‐creation services mentioned in the previous PDF or use Right Banner, which is owned by BuySellAds and will create banners for you very cheaply on request.
BlogAds BlogAds.com allows you to purchase banner ad space on popular blogs, and you have the option to pay by the week, two weeks, one month, or three months at a time, so you have a lot of options if you just want to test or lock in a successful ad placement over a longer period of time. They also give you the option to pay with PayPal. BlogAds tends to have odd–‐shaped banner sizes that you won’t find in the CPA networks, but you should be able to have banners created for you for free by the network’s in–‐house designer.
TraffiQ Like the sites above TraffiQ allows you to purchase banner space on popular websites, but you need a minimum deposit of $1,000 in order to create a campaign. The process is a bit different from that of the above sites, as well. Rather than the entire process being automated (aside from the review of the ad for suitability), you have to submit an “RFP” (Request For Proposal), including how much you are willing to spend, how long you want your campaign to run, the minimum site traffic you are looking for, and your “campaign goal” (I always put down “enhanced targeted leads”). You also have the option to select CPM, CPC, or both, but most sites only accept CPM. You can also specify site type (blog, forum, etc.), target demographics, site category (auto, electronics, games, etc.), ad size preferences, and “deal points” (this includes your “out clause,” allowing you to cancel your ad placement within a certain time frame, and your “frequency cap,” allowing you to specify how many times you want particular visitors to be able to see your ad – this can help ensure you get more unique viewers). In addition, TraffiQ allows advertisers to communicate one–‐on–‐one with site owners, which can sometimes allow you to negotiate better rates. If you don’t have at least $1,000 to spend on advertising upfront, you might want to concentrate on some of the other networks first, and then begin reinvesting your profits in higher–‐end media buys once you have the cash flow.