There are many forms of advertising you can utilize on the 
Internet. For example, there are a number of programs 
referred to as "Pay Per" programs.
These programs include, pay-per-click, pay-per-lead and pay-
per-sale. 
Pay-per-click programs will enable you to advertise to your 
target audience and only pay for results -- you pay a set 
amount for each visitor that is sent to your web site. The 
most popular pay-per-click program is the pay-per-click 
Search Engines. You can learn more about pay-per-click 
Search Engines here: 
http://www.payperclicksearchengines.com/
Pay-per-lead programs will enable you to only pay for 
leads. These leads may be potential customers that fill out 
a registration form, enter a sweepstakes, or download a 
free product trial.
Pay-per-sales programs are simply affiliate programs. 
Affiliates are paid a set commission for each qualifying 
sale.
You can find a number of Pay-Per programs here:
http://www.clickaffiliate.com/
In addition to the above Pay-Per programs, you can purchase 
pay-per-click banner ads. There are several companies 
online that will place your banner within their network and 
charge you a set fee for each click through. 
Value Click 
http://www.valueclick.com/
AdDynamix Pennyweb 
http://home.pennyweb.com/
Another popular advertising technique used on the Internet 
is pop-windows.
Although the effectiveness of pop-windows has declined (due 
to software programs that prevent them from loading), pop-
windows can still be an effective advertising tool.