I don't know if the dancers are not getting any sales training but some of the SC joints that I go to, I find myself sitting alone at my table for more than an hour before anyone approaches me. I can understand if everyone is busy but many times I go into the club and see as many as 5 dancers at the bar playing video poker. Do they have GPS or are they just slacking? Maybe I give them too much credit in comparison to how a car dealership works. On one hand, you don't want to harass the customer who says he's "just looking" unless he has questions. But typically you check in on them every 10-15 minutes or so. At the least, you watch them and judge when it would be a good time to engage with them. Like if someone is standing on a car lot looking around at everything other than cars, chances are that they need a salesman. So when I'm in the SC and I'm sitting at the table looking at everything other than the featured dancer on the stage, chances are that I might be looking for some company.
And then I consider that it may have something to do with the management. Is the owner/manager teaching the dancers how to work the room? Are they teaching the dancers how to observe the crowd? Or are they just left on their own to figure it out? I see guys walk up to the bar asking for dances but that's not how it's supposed to work. If I am a paying customer, they should be asking for my money. I shouldn't be asking them if I can give them my money.
In situations like this, it's interesting how they just act like a bunch of sea-gulls jumping on the same piece of bread as soon as the first one notices food on the ground. Maybe I look like I'm broke but it seems like when I get that first dance 90 minutes later, everyone else starts coming to my table. Sometimes to make a point, I'll spend all of my money on that first dancer that approached me. Then after a 10 dance run, the next one will come along and I will explain to her (in a nice way) that I'm all out of money.
I understand that there are a lot of tire-kickers and cheapskates that come through the club but that's no excuse to not work the entire room at least once or twice during your shift. You never know what might come out of it.

