Not all networks are the same. The CEO of Undertone Networks offers this guide for choosing which will work best for your needs.

As you allocate your budgets online across search, email, display and other vehicles, it is important to have a relationship with an advertising network. It is equally important to be sure you have that relationship with the right network, one that works best for your business. With more than 100 networks in the marketplace, both advertisers and publishers have numerous choices of who to work with. These guidelines should help advertisers in their decision-making process.

Be sure to choose the right type of ad network
Not all networks are the same. Advertising networks can generally be categorized into three types:

1. Sales Representation: In this model, the network acts as the outside sales force for the website. Networks that employ this model include 24/7 Media and Winstar.
2. Revenue Share: In this model, the publisher and the network share a percentage of the revenue gained from the sale of the ads. Networks that employ this model include Burst Media and ValueClick.
3. Pre-Buy: In this model, the networks buy inventory from publishers in advance, packaging the media into verticals and various targeting segments. Networks that employ this model include Undertone Networks and Advertising.com.

It is important for the advertiser to know how a network operates and how they buy their media because in order to craft a good buy you should choose different types of networks. You don't want to work with networks in only one of these categories. For instance, if you work with all revenue share networks, you will have a fair amount of site duplication. Additionally, some of the larger networks will say that their network will provide all the reach and technology to meet your objectives. But this argument is the same as just buying Yahoo! and not AOL or MSN. Spread your budgets around and make sure you are trying some of the top networks in the space.

Be sure your ad network includes quality sites
As a media buyer you also want to know what kind of inventory you are purchasing. Complete site lists are not imperative, but do request examples and screen shots of your ads once the campaign is live to ensure that your ads are appearing on acceptable sites.

Some of the best networks may not be able to divulge site lists because of contract agreements with their publishers. However, be sure to ask if a network includes spyware/adware inventory. Find out if a network has user-generated and social networking content.

You will be surprised to find that many of the top networks get a large portion of their inventory from MySpace and then try to use their technology to mask the fact that this inventory is the second coming of personal web pages that first sprouted up with Geocities and Tripod.

Be sure you know where your ads are appearing
Another thing to be on the look out for is re-brokering or network sharing. As marketplaces emerge and co-dependent network relationships develop, you will find your ads being bought and sold numerous times over. Avoid this by asking how a network operates, confirm that they are delivering the media, and be sure that they put their answer in writing.

If you are focused solely on CPA then these issues may not matter, but as the market grows and more top brands come online for both branding and "softer" direct response, it is imperative that you push for these safeguards.

When it comes to optimization, find out if the process is fully automated or if there is a human element. For CPA campaigns you may not care where your ads run, thus an automated system might work fine. But if you are looking to ensure certain quality controls it is important to know that there is a strong and durable traffic/client services team in place. 

Be sure your ad network has experience in your market
When considering a network find out what type of experience they have. How long have they been in business, who is on their client list, can they offer case studies, testimonials, et cetera. This information is important.

Find out if this network has worked with your direct competitors or at least in your general category. Knowledge, prior data and working history do make a difference. If you work within an agency find out if any of your colleagues have worked with the network before and get their opinion.

As a side note, ask your network what else is in the product pipeline. Networks sit in the very favorable position between buyer and seller. They have good information and working industry knowledge that you can leverage for your own clients and planning purposes. Learn what's on the horizon-- it might give you some insight and better information to help you plan.

Be sure your ad network is known and has stability
Lastly, know who you are working with. The barriers to entry in the network business are non-existent. It's easy to call an advertiser, claim to have a network and then purchase lower quality inventory to fulfill the business. Be wary of these operators; you don't need them. There are a handful of legitimate players that have been in business for years, working and are well experienced.

Visit the network's website (i.e. make sure there is one), and check out the management profiles. You do not want to allocate budget to a questionable outfit, as you'll only deal with the headaches later.

Additional resources:
For lists of ad networks and their capabilities, see Ad Networks Crib Sheet and Ad Networks Crib Sheet Part 2.

Michael Cassidy founded Intercept Interactive in 2001 and serves as the company's president and chief executive officer. Shortly after founding Intercept, Cassidy launched Undertone Networks, a premium online advertising network. Read full bio.