The number of sites on the Web today is almost infinite, with new ones popping up every day. There are multiple types of sites: portals, "brochureware," content sites, directories, search engines, and ecommerce sites, to name a few. Those that do not sell product or services directly or indirectly on their site often rely on advertising revenue to support operations.

So how does one get started getting companies to advertise on a site? Here's a quick primer to getting out of the gate.

Google AdSense

Probably one of the most simplistic ways to place advertising on your site is to sign up with Google as one of its AdSense
Publishers. The Adsense program displays text ads rather than images on your site. Google then serves ads based on the content on on the page containing their ad code. For example, if we post a tip on our site about email marketing, Google ads will likely deal with email marketing services or products (see our archived tip, How Email Formats May Affect Response Rates, as an example).

Just in case any of your competitors show up in these text ads, you have the option to pre-block them with an ad filter.

Google pays a percentage of the revenue it earns (it does not disclose exactly what that percentage is) and sends checks to publishers monthly, provided that the publisher has generated at least $100 in ad revenue.

Affiliate Programs

The next easiest way to get advertising on your site is to sign up with an affiliate program (or multiple ones) as a publisher. You will then have access to listings of hundreds of merchants (a.k.a. advertisers) who offer a financial incentive for you to promote their products. Though typically you only get paid when there is an actual sale (versus getting paid just to display their ad), all you have to do is place the ad on your site or in your newsletter, etc., and the affiliate program will take care of the rest.

Some of the most reputable and well-known affiliate programs are:

* Commission Junction
* LinkShare
* Affiliate Shop
* Commission Soup
* DarkBlue
* Amazon Associates
* Primary Ads
* Affiliate Fuel

Ad Networks

An ad network is essentially one centralized re-seller of advertising space which brokers sales for its network of publishers at mass or liquidated pricing in exchange for a percentage of the ad buy.

There are various ad networks out there and joining them is rather easy, but before you do so you should ensure that your site is up to date and meets the criteria of the network. Typical criteria include:

* Minimum page views or visitors per month - Some networks require little or none while others want anywhere from 3,000

to 250,000 page views a month or thousands of visitors per month
* Content - Your site content should be relevant and regularly updated
* Targeting
* Residing on own top-level domain - Your site should not be hosted on free providers
* No excessive amount of advertising - A site cannot be all advertisements because that won't appeal to anyone
As a publisher, you just don't want to "give away the shop" and sell your soul for a bit of advertising revenue. Here are
some particulars to be aware of:

* Percentage of revenue - Legitimate networks should give the publisher the lion's share of the advertising revenue;
somewhere in the neighborhood of 55 to 70 percent of revenues generated by the site is common

* Exclusivity - Avoid ad networks that do not allow you to serve ads from any other network
* Payment terms - Many times you will not be sent your check until 30 to 90 days AFTER the month in which your balance has
reached a pre-determined amount. * Dependability - As with anyone else you might be hiring, contact some other sites
* Publisher veto power - Like Google AdSense, does your ad network give you the power to reject specific campaigns or ads
shown on your site?

Feel you are ready to accept network advertising but don't know where to start? Here's a list of some small to mid-sized
ad networks to contact:

* Search Feed
* Adtegrity
* BlogAds --specifically for blogs
* Burst Media
* Fastclick
* ValueClick
* x10 Networks
* Clicksor

For sites attracting visitors on a larger scale, some networks for you to also consider include:

* Blue Lithium
* AzoogleAds
* Advertising.com
* MaxOnline
* 24/7 Real Media
* Ad-Up

After you have met the requirements needed for a particular ad network and have decided to sign up, you may also want to keep a few things in mind. Without a doubt you should read the contract word for word and make sure you comprehend all of the information. Then take into consideration the ad rates, types and formats. Would you like to offer targeted or non-targeted advertisements or both? Just don't throw caution to the wind for a quick buck. Be sure to retain the upperhand when dealing with any kind of advertiser or advertising network. It is, after all, YOUR site.

About the Author: Hollis Thomases is the President of Web Ad.vantage, Inc., an online marketing firm specializing in search engine optimization, paid search engine marketing, and online media buy.