Network effects in buying

I have been thinking about the “network effect”. Developments this spring with Flickr have made it a less desirable website to host pictures. In the meantime, one of my brothers signed up, then showed up as a “buddy” when I logged in. One little thing like that made Flickr more desirable then when I was using it by myself. Now if I move, I have to consider getting my brother to move to, and frankly, I’m not even interested in his pictures. This article from the NY Times goes off in a slightly different direction. What happens when early adopters pick a direction? Although it is considered somewhat unpredictable, the possibility exists that those early adopters can pull a market in their direction. This article was about music, but examples such as websites or software to use (Facebook anyone), what cell phone company you use (Verizon in my case), or what brand names are purchased can be affected by a relatively small group of people.