Ain't Love Lucrative!
A "Valentine's Day Consumer Intentions and Actions Survey" is clearly something to be taken seriously. However, it's just the tip of the informational iceberg when it comes to research into the economic aspects of Valentine's Day, the third largest spending season in the US.
If you want to be informationally immersed, look over the whole detailed survey, current and retrospective.
However, it's just possible that you'll find that more than a little daunting, so here's a lighter-weight option that will tell you (among other things) that 3% of pet owners give a V-Day gift to their pet. Suburban Chicago's Daily Herald, looking for a new slant, picks up on an organic Valentine's Day trend in Schaumburg, IL.
Find this article at http://thelibrary.org/blogs/article.cfm?aid=71&lid=46