From my experiences, maybe 85% of the time if you ask for her number and she says no, but wants you to come back, it's purely for money.
However, there are some girls who may actually like you, but they won't give you their number the first time they meet you. These girls have to beware of psychos and stalkers....If you're not hiding anything (wife, gf, etc...) just give her your number and she'll call you if she is truly interested.
Depending on the strip club, there are also girls who cannot be seen leaving with or giving out their number to clients. I know of a few places where if a girl is caught, the management charges her $100 thinking she is leaving with the client as a 'prostitute' and if she won't pay they fire her.
One of my ex GFs was a stripper in Montreal and I"ve also picked up and fucked (free) quite a few in the past. Above is just some of my views on it
