what is the best page to advertise on? Or are there others that get a lot of traffic like eros?

tryst (dot) link seems to be increasingly popular with girls in your price range. I check there. Still check Eros. Here as well.

I'm TS provider so factor that in to my comments. For +5 years I've tracked where practically every client contact has originated & Eros has always been the leader. Kills me to say that since the monthly cost is a chunk of change and a half (plus since SESTA/FOSTA, the fee increases can be totally ridic).

I've known providers that have had success with Adult Search, but it didn't work for me. Even worked with customer rep to promote ad with some targeting enhancements, but the return on investment just wasn't there. And I think sometimes that a site might be a fine fit for some providers but not others.

Something I do from time to time, is open an Incognito Window in Chrome (some browsers call it Privacy mode or the like) and type in various search terms that I think hobbyists might use (e.g., "los angeles transsexual escorts" etc) and see which ad sites appear high in search results.

When I try a new site, I give it at least 6 months, freshen the ad bi-weekly, and then track what happens. TS4Rent worked out for me that way. I wish they had a non-TS site for you to checkout since they're pretty good peeps to work with.
Be safe & prosperous!
xoxo
Kacy TGirl

You don't mention your method, but  
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This has come up several times, mostly on Newbie, as I recall:
http://www.theeroticreview.com/discussion-boards/newbie---faq-33/some-reasonable-explanations-165468
http://www.theeroticreview.com/discussion-boards/newbie---faq-33/sometimes-i-say-the-other-ad--140692
http://www.theeroticreview.com/discussion-boards/newbie---faq-33/somebody-should-get-an-mba-for-a-study-like-this-140657
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Focusing on phone numbers, some guys are suspicious of 2 or more phone numbers. It used to be one of the easiest ways to do market analysis for ROI on advertising expenditures. Phone #1 is the Eros ad; Phone #2 is Slixa; Phone #3 is the index card on supermarket bulletin board; Phone #4 is the bus station men's room; ...  Remember, when determining ROI, it's not just the number of contacts but the number of completed transactions.  
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There used to be a guy with an escort blog that took paid advertising, mostly from AMPs and RMPs. That's how he "sold" a lot of ads. He'd give potential clients one month free (or cheap) but they had to use a separate phone number. Guys following his popular blog lit up the phone (and closed the deal) more than any other advertising they were using. You can bet dollars to Bill's donuts that market analysis worked for them!
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NOTE: If you are just asking someone "Where did you find my ad?" you might not always get an honest or accurate answer, especially if there is significant discriminator. E.g., if the rate on the Eros ad (a high end site) is $400 but the rate on the foxylists site (a lower prestige site) is $300 and they have seen both ads, they are going to tell you foxylists, for sure!

thanks for listing those other discussion threads (I knew they were out there from prior times I've replied to similar Qs, but i'm too lazy to go & find them
btw, my index card on the supermarket bulletin board has an excellent reply figure, but putting my number in the bus station men's room has a much better conversion rate :-P
xo
KT

i miss backpage a lot, I couldn't find yet another website who bring contacts world wide like the old backpage.

Learning to use Twitter, is a good and cheap tool for publicity.

Unfortunately EROS have some european countries like UK and Italy but they are not interested to ad Spain on their list.  

:´(