Here's more information:
In the past 12 days (March 1st through 12th) we had 12,378 visits come through a Google search.
7,219 of those were into the plant database.
4,047 were to one of the many plant pages in the database.
2,952 were to one of the many full size photo pages in the DB.
Compare that with 3,822 by Google searches that came to a thread in the forums or elsewhere.
The database is responsible for well over half of all new visits to the site.