Network effects: it's difficult to dislodge an entrenched competitor once they've accumulated a large enough dependent userbase. However, a number of other ser

Network effects: it's difficult to dislodge an entrenched competitor once they've accumulated a large enough dependent userbase. However, a number of other services are chipping away at Craigslist, developing their own userbases in niches that Craigslist used to occupy. (e.g. Tinder)