[davidw]

Crossing the Chasm also talks about this: it's very, very difficult to beat an established company at their own game. You're more likely to do so by attacking a niche they are not interested in, or are weak in, and growing from there.

[jacquesm]

Establishing a beach-head is a very slow road but it has a good chance of success. What I'm getting at in the post is that there are some game-changing circumstances at play since those companies were founded and they all appear to have huge, not so easy to fix blind spots. That creates opportunities. Compare ebay or Google with Amazon and Zappos. I definitely do not see Amazon and Zappos as vulnerable when it comes to their core, Google is at its core not a search engine anymore but an advertising company and exactly there they are left wanting. Ebay is hurting badly right now, someone that moves fast might be able to inflict serious damage before the window of opportunity closes again.

Naturally, none of this is going to be easy. But I think it just might be doable.