Ask HN: Is TripIt a product or a feature?

There have been a few articles recently pushing the notion that "TripIt is a feature, not a product". I think the functionality is pretty good. This makes me wonder "if TripIt is a feature, what would I call my minimum viable product?" A micro-feature?

Pretty intimidating, especially since I have a tendency to be critical of my own product ideas that aren't "full-featured" enough. I can easily talk myself out of testing a new product in the market because "it's just not ready". Of course customer development doesn't require a working product, but I hesitate nonetheless.

What constitutes a product vs. feature to you? Do you ever let the concern that you don't have enough features prevent you from releasing?