Demand Media said on Thursday that a drop in search engine referrals and weak advertising sales sent its revenue down for the first time since the company made its public debut nearly three years ago. Demand Media, which owns the websites eHow, LiveStrong and Cracked, mainly makes its money from articles and videos that surface high in search results. We are going to invest in areas of growth.” Founded in 2006, Demand Media was a closely watched experiment in how to create inexpensive content by tapping a network of thousands of freelancers for “how to” videos and articles. The problem with Demand’s business model is that it is too dependent on Google.