Most SEO companies offer different types of online advertising. The key here is to make sure that the campaign works for you and that the company delivers.

Investing on ads for websites is an effective way of online advertising. Contextual links are better though as most entries in blogs with good page rank often get indexed quicker.

Google still leads the pack among online advertising companies. However there are more SEO companies stepping up and I am sure it will be healthy competition and in the end will benefit the advertisers and consumers alike.