Hi Vicki, I wouldn't give anybody a song without a contract or written undertaking. Imagine if some well known artist wanted to use the song in the future. If it became a hit, then this guy could use that as a marketing stunt to sell 'his' album, but with no financial gain for you.
I have been on a couple of compilation albums in the long distant past. On both occasions I had a contract that a) split the income 50:50 with the artists after costs had been covered and b) specified that the song was provided on a strictly single use only, and bestowed no ownership or copyright to the indie label.
Even if he only makes a small profit from his albums, I always think the creator and owner of music should share in any income, however modest. Songwriters and artists are too often expected to provide services for free, as we all know.