It depends on where and when I advertise. I have Google Analytics, and where I get the bulk of my traffic with the least amount of effort is where I buy the advertising. For example: when you're on a site where there are a MILLION girls and you still get the most traffic from that site,(for me that's Punterlink) I would step up my game and get a featured listing. If I'm on a site, and I don't get very much play at all, say a local review board, and I only get spikes of inquiries when I post something, and they offer banner advertisements, I would buy the banner placement for a month, and post as much as possible, and if it doesn't do well, or you don't get ANY bookings, I dump it.
It's not about what other ladies are doing. Just analyze your own business, and set goals to do better than you have been. Compete against yourself. If you need any help, just pm me.
Happy hunting!