1. Under-monetize to buy mindshare. (almost every category Google is in)
2. Offer a free version to make sure everyone who may want to has a chance to experience your product and/or service. (almost every category Google is in)
3. Offer something that forces people to keep coming back to your website. Alternatively, bundle your stuff into the browser. (the Google Toolbar is huge.)
4. Invest heavily in distribution deals and public relations. Keep making small changes and talking about how important they are so you stay in the media. Maintain that your success is because superior products even while you are buying marketshare.
5. If a business model competes with your model, try to guide the conversation and get market participants to attack each other to your own benefit (this, above all other reasons, is why it is not smart for “professional” SEOs to publicly endorse outing each other…nobody wins but Google).
6. Offer free or low cost versions of cash cows of competing services to distract them and/or force change upon them. (Google Docs)
7. Even when you have a market leading position, keep investing heavily in complimentary markets to reinforce your position as the default. Become ubiquitous. Become a verb. (mobile operating system)
8. When you tap out the potential of your product or service look for ways to make it deeper is select high value verticals. (onebox, universal search, site search)
9. When you have enough leverage and a large enough lead, change the market to put yourself at the center of it. (the Omnibox in Google Chrome)