HipChat is a good example of first-mover complacency. They had one of the first really solid workplace chat solutions, grew a big userbase, got acquired, etc. But they never iterated or kept up with changing trends, so they got caught off guard by a well-executed competitor.

Another lesson here is that no established product is too big to go up against. I often see people rejecting startup ideas because there is a single competitor offering the same service. Competition is not a reason to forego building a product. If anything, it's a positive signal that your product has a market.

You can make a solid business just by fixing existing products and/or offering the same service for cheaper because you have some efficiency that the incumbents do not. In fact, sometimes the incumbent has set their prices so high because they have no competition, and inflated their expenses so much that they couldn't match your prices even if they wanted to.