Rated as a negative and here is why...
Many of my friends have left facebook. With facebook forever making changes to the home page and layout, many have become upset with the changes and how buggy / error prone facebook has become. facebook also has had many viruses. not a problem for mac users, but for those using itunes on windows that makes them even more vulnarable.
Also there is a rumor that facebook (with all it's games, advertising, etc) may start charging users $4 a month in the upcoming months, due to server overloads and the cost to keep up and running. I know if that ever comes true, my 140+ friends said they will leave facebook.
I left myspace due to being hacked a number of times, it is only time for facebook to face the same issues. facebook may also turn out to be a fad (unless some big company starts supplying them with money to improve it, since there are so many using it and apps making connection options). Once facebook goes, what is next.
Also what about LinkedIn. I use Facebook for my personal agenda and LinkedIn for my business groups. just this week alone, I was asked to join 3 other social networking forums I never even heard of. Where does it end, so many to keep up with.
And if facebook is the chosen method, by God update the iphone so that I can play the videos people are posting. I mostly use facebook from my iphone anyway. oh wait, facebook uses flash.
