We discussed which ad networks to use for earning money from your sites here. But if you want to drive traffic to your websites the two big ones to check out are:
If you want to advertise your product with Google ads you use Adwords. If you want to earn money from Google ads you use Adsense. Just as Adsense pays more, Adwords costs more than other alternatives. Clearly if you do it right you can deliver the right kind of creative to the right audience with Adwords. This is particularly true if you are targeting search engine traffic or visitors to ordinary websites. However, setting up and tuning an ad campaign in Adwords is not at all easy. I’ve lost a lot of money on Adwords campaigns for two reasons. 1) lack of expertise in creating and managing campaigns. 2) trying to sell products that were not particularly well suited for Adwords. For example, my website investing course was not a great candidate for Adwords because no one has ever heard of website investing. So it was hard to find search terms that narrowed the audience enough to make my campaigns cost effective.
I’ve had some success with Facebook ads because they can be targeted toward very discrete audiences. You can target people who have liked certain categories of things, joined certain groups or are members of certain demographic categories. To illustrate the difference between Adwords and Facebook ads, consider the scenario that you are selling a “dog leash”. In Facebook you can target people who are part of the “Chicago dog walkers” group. In Adwords you can target people who search for the term “buy dog leash”. There are pro’s and con’s to both strategies.