No, actually, the benign lock in comes from customers and developers relying on your data and the value they themselves add to it, not on ownership of the data itself. For example, much of the core data on Amazon is also available on BN.com or other book sites. It's what customers add to it that is unique. And the same is true of added-value applications.
One of my all time favorite quotes about the computer industry came from Doug Carlston, founder of Broderbund Software. He was explaining their various product lines: games (like Myst), "infotainment" (lie Where in the World is Carmen Sandiego), and productivity software (like Print Shop Pro and Family Tree Maker). "Family Tree Maker is productivity software?" I asked. "Yes. We consider anything productivity software when the user's data is more important to them than the data we provide."
Sites like Amazon have a lot of user data, but they are not yet quite "productivity software" by Doug's definition. The "lock in" I refer to comes when they have that extra edge of value for users.