I believe it, I used to be involved with an 'ultra lounge' here in Indy and the owner and I had tons of people in our contact list we'd call and send text messages to when we were having a slow night, mostly mid 20's women. We'd tell them to come out, give them a few house shots free which were mostly orange juice with a splash of alcohol, and then people that would walk in would be far more inclined to stay instead of immediately leaving, the girls would often get a drink or two bought for them off walk ins too then they'd usually leave within an hour or two to places more in their price range on the same block and we'd have effectively drawn a self-sustaining crowd.

We'd also put out the brass posts and rope sometimes on slow nights, simply appearing like it was going to be busy enough to have to manage a line was often enough to get people to linger longer.

If a big group came in, like a bridal shower doing a bar craw, we'd usually keep them around longer with a couple of rounds of the house shot too just to keep the female to male ratio up. Eating a few bucks per round of IVs was almost always a good spend in that case.

I'd take the term "friends" loosely. A club promotor likely has a ton of people they know and could call on.

If they were in college, university or first real world job, it’s very likely they had lots or acquaintances they could tap for mutually beneficial help.