The first and foremost reason a dancer wouldn't get as much attention in a club is because they haven't been there long enough to be regarded as a 'regular'. I'm not talking a few days - it takes weeks, maybe a month or two, before club regulars recognize you and associate you with someone having an engaging, fun personality.
The second reason is usually because of the avatar. I haven't met too many people in
SL who like hearing that their avatar shape and skin needs work, but the fact is that a large percentage of avatars in
SL are disproportioned, unrealistic, sometimes cartoonish looking. Sure, this is subjective, but if you look around at other avatars and take mental note you'll eventually see where you might need to change some things.
For females, the hardest things to get right are usually:
* Face - the standard face is ok, but not unique. Most of the shapemakers in
SL don't vary much from the median norm when it comes to face. But I also see eyes that are too large, oversized lips, sometimes cheeks too prominent. That sort of thing. If you're not adept at working with the appearance sliders sometimes it pays to spring for a pre-made shape until you master the art.
* Boobs and butt - I remember a comedy show once where they did a faux survey on the street. The girl taking the survey did the first part with her boobs bound tightly and covered. She hardly got anyone to answer her questions. In the second segment, she showed off lots of cleavage and the difference was remarkable
I'm not saying you should crank your sliders out to 100 - that's the wrong thing to do. You can make a very nice chest with sliders in the 60-70 range if you manipulate cleavage, sag, etc. Same with butt -- anything over about 40-45 is going to look like you were created in a Robert Crumb cartoon.
* Skins - I think it was Beebo who once said that she never alters her shape to suit a skin, but looks for skins that compliment her shape. That's great advice. But here's the rub: A good skin will run you $800 to $1200L. That's 3 or $4 USD, but how long will it take you to recover that in tips? It's like a catch 22, and I suggest to prospective dancers that they would be well-advised to already have the skin, shape, hair and clothes before they take up dancing for money.
* Clothing - see skins. Dancers are a bit different than other avatars, in that your goal is to dress provocatively to attract attention. I'd be on the lookout for stores that offer that sort of clothing at good prices - Haalsa Hallard, Decadent Designs and "FuK'N'Hawt" are three that come to mind right off the top of my head. You should be able to put together a good assortment of miniskirts, latex, and lingerie for about $1000L or less.
Bottom line: Dancing with the intention of making money is almost a zero-sum game, especially at first. It takes money to make money as in all things. If you're intent on doing this, make friends with the other dancers, get their advice, and get lots of face time at the club - eventually people will know you on sight and you'll find things go a lot easier.