Pay Per Click [PPC] Advertising
The principal behind Pay Per Click advertising is quite simple. In exchange for listing your advertisement in search engine results for selected keywords or phrases or on affiliate websites (usually alongside or above the purely editorial listings), you pay the search engine a certain amount for every click that the ad gets. Being that most PPC system are auction based, the amount you pay for each click is dependant on how much you bid. This amount also determines how high you advertisement is listed in comparison to your competitors' ads.
The 'opposite' version is where you carry advertisements from these programs on your site, earning income every time a visitor clicks on one of the ads.
Visualeze can offer advice on the best option for you [assuming you decide that these programs meet your needs] & even run campaigns for you.
Google Programs
Adwords appear as small sponsored links that appear on the right hand side of the search results page on Google. They consist of a title, which also acts as a link, two lines of descriptive text and your URL. They operate on a pay per click basis and are keyword related so your ad only appears in search results which are fairly relevant to your site.
AdSense places text and image ads on your site. They are targeted to be relevant to the content of your site although this could mean you end up showing ads from your competitors. If you add a Google search box to your site, AdSense produces a search results page with relevant text ads based upon your visitors’ search request. Revenue is generated in relation to the number of click throughs that these advertisements receive.
Typical Google AdSense presentation
Chitika Program
A relative newcomer to the pay per click advertising world, Chitika eMiniMalls is an equivalent solution to Google's AdSense scheme. They provide more interactive & graphic adverts compared to Google and can be used on your site alongside Google ads.
Yahoo! Search Marketing
Previously run under the Overture banner, this is Yahoo!'s answer to the Google advertising products above.