The people who run these brothels and shops generally have little knowledge in marketing/advertising. If they did it properly they would offer discount rates to regular customers for positive reviews on Google liating/maps so it would show top 3 (locally) and pay someone for decent search engine optimisation and try get top two organic results and maybe small budget on google adwords and drive as much relevant traffice to their site, track with analytics and adjust as needed.
I run my own business and this approach is pretty effective. Word of mouth/reputation/trust can not be underestimated either.
The good thing about selling sex or any vice for that matter is you'll always have customers. Its a matter of making it as easy for them to find you.