The Myspace to Facebook example is funny, because Facebook was the anti Myspace. Not only that, they were the anti Myspace specifically because they stripped out features.
Many successful companies were the anti-something or another when they were small:
* Google was the anti-Yahoo
* 37 Signals was the anti-enterprise (and lately, the anti-funded startup)
* Southwest Airlines is the anti-American Airlines, don't you love their free baggage commercials?
* Reddit is the anti-digg