How many websites can help the company to advertise their products on the Internet?

[simon]

[Jake]

There are ad networks like Google's Adwords that may have 2 million sites selling ad space which you can access with their self serve ad system, realistically one generally has to select a relatively small number that have a demographic match to your product or service, although networks may offer "site wide" remnant ad space for a reduced price that may be usable for products with universal appeal. You can slect individual sites or pages on which you want your ads to appear.

Some ad networks offer "blind" traffic from unnamed sites that are select based on keywords you provide, you may have a chance to optimize a campaign by eliminating certain site #s.