"The Scorpion King" has been #1 for two weekends now, with gross receipts of $60.8 million. After doing some looking on imdb.com, I've calculated that Rock has, in two weeks, outearned every movie that Hogan has starred in - PUT TOGETHER (box office gross: less than $30 million - including "Three Ninjas: High Noon at Magic Mountain").
P.S. If you want to include Rocky III ($123 million domestic) for Hogan, I'll insist that you include The Mummy Returns ($202 million domestic) for the Rock.
I'm going twenty-four hours a day...I can't seem to stop - "Turn Up The Radio", Autograph
With Hogan's movies the attraction was that it was "Hulk Hogan", the attraction wasn't that it was a good movie, or even a movie that anyone would see. No Holds Barred was made under the assumption that a wrestling movie could draw with Hogan(it couldn't). Santa With Muscles and Mr. Nanny were based on Hogan drawing as a wrestler in a "fish out of water" role as a kind hearted, comedic hero, which rarely ever draws no matter who is in that role (except Arnold did it in Kindergarden Cop. To a lesser extent, Three Ninjas: High Noon at Magic Mountain was to blame more on the francise falling apart than Hogan (though Hogan had already shown that he wasn't box office material at that time). To the other extreme, as you said, Rocky 3, though that really was based more on the success of the Rocky series than on Hogan's power to draw fans.
Now contrast that with Rock. Rock's in the enviable position of being in a movie that has a successful franchise behind it, with steam left from Mummy 2, he doesn't suffer from bad overacting like Hogan, he's better looking than Hogan, and he's gotten good reviews. Also, he's able to take full credit for this movie (unlike Hogan where, Stalone obviously took it for Rocky 3) and thus can claim almost entirely the success of this movie for himself. Add to that the fact that the movie has cross-fanbase appeals (wrestling fans will see it because it's The Rock, action fans will see it because it's an action flick) and excellent timing (Movie going fans are prepping for the big summer run of Star Wars, SpiderMan, and ostenibly MIB2) that it was hard for Rock not to fail. Now he's a branded success, it's time for him to deliver on a follow-up (Helldorado makes me squeemish) or do what Hogan did and pigeonhole himself into certain non-money making roles.
Rock's got the talent that I think he'll do well, but to compare his movies to Hogan's is apples and oranges (not to say that it's an unfair to compare them in this situation, but they're really two totally different things)
As a former assistant manager at a large chain drugstore, I can verify that Mystery Shoppers exist. What I don't know is who they contract with for the work. I don't believe there is a large corporation for Mystery Shoppers.