[dchuk]

This is exactly right. By offering a truly free option (not a free trial) you're planting a seed in the user's mind that they can, in some way or fashion, get your product for free. In some form, your product is free.

This will shape them psychologically to be ok with the lesser free version in most cases.

Freemium does work, but not just because it gives users an opportunity to try something out with no risk. So do free trials. Very very few companies actually do freemium right, and would stand to benefit from a free trial instead (which doesn't have the same psychological implications that a truly free plan has)