I think I'm most impressed with the Eden Food response - someone actually took the time to consider the individual letter, then sent a surprising amount of free merchandise based on the request.

Who knew Corporate America could be that nice? ...then again, the general trend seems to have been the smaller the company, the nicer and more personal their response....

I did this some years ago (24 years ago to be exact) when girl child was an brand new infant. I sent letters to diaper companies (blah blah, how great the product is, etc) and one company sent a of 24 boxes of newborn size diapers.

gross.

She feasted on fresh diapers for a whole month after sending the newborn back in the empty box.

haha.

That's so awesome.
I am gonna do that, but only with 10 stamps because I have no job.