Well, according to an X17 spy at Staples Center last night, it's not nearly as fun as it is to be in the audience!

For one, there's no cocktails (no alcohol of any kind, actually) allowed - ever! But there were "MOCKtails", so the industry insiders could enjoy virgin versions of their favorite drinks.

The food provided for the pre-show guests was "southern-style fried food," which apparently was insisted upon by Jamie.

But the food's not the only thing Jamie's controlling at the Circus, Britney was never seen backstage, "she is under lock and key," according to our insider.

Other Circus "fun facts": The Pussycat Dolls have never even been invited to meet Brit. There's virtually no interaction.

There's also random drug testing that all the performers have to submit to on a regular basis.

Although the backstage area might have been about as much fun as a cold shower, it sounds like the normal folk got quite a show last night -- our spy described the atmosphere in the audience as "a huge party!"