Top categories by revenue generated from Econsultancy: PPC, True-Content, Blogs & Forums, Social Networking, Cashback & Reward, Email marketing

A few nice Network advertising images I found:

Top categories by revenue generated from Econsultancy: PPC, True-Content, Blogs & Forums, Social Networking, Cashback & Reward, Email marketing
Network advertising
Image by Matthieu Dejardins, eCommerce Activist
Illustration from the following post: Affiliation Program: motivations, EPC, top 20 publishers & network comparison.

Paid search or pay-per-click advertising (PPC) is the most significant category for US affiliates (48%), marginally ahead of true content (SEO) on 46% in terms of the amount of revenue they help to generate. Just under half of affiliates surveyed say that each of these methods is among the most important to them.

Blogs and forums are an important category for 40% of affiliates. Social networking (24%), cashback & reward (23%), email marketing (20%) and coupon codes (19%) are the next most important methods.

Session: The Truth about Social Network Advertising
Network advertising
Image by pixelberlin