Well, I know a lot of people break up around Valentine's Day so I'll say Divorce business. :-))))

restaurants

greeting cards (Hallmark)

Jewelers

Lingerie

Teddy Bears

Hotels/motels

Babysitting so parents can have a few hours to themselves

Divorce lawyers was my first guess.

And I agree with everyone else's guesses so far, too.

Rusty

I agree with the liquor stores thing. Lotsa bubbly.

divorce lawyers when all the above gifts don't appear.

Movies

Prophylactics (just to say something different!)

Ummm... escort services?

Delivery persons

Movie Theaters

Bakeries

I think jewelers too....

Resturants