CL and the scrapers that steal your stuff from bp is all I know of. There could be something else out there.  

This may be regional, but where I am there's a number of escorts advertising on the bp massage. You don't seem to need a sm link there. Last I heard it's 8 bucks a pop though.

There doesn't seem to be any need for a real SM account, just a link.

I believe their ads are free. There are other free ad sites but your location may dictate which are popular in your area.

As to BP, I noticed that they are now requiring the ladies advertising under women for men, to post a SM link (Facebook, Instagram) but I also notice that most ladies are posting BS links anyway. (Links to other people's accounts, celebrity accounts, animals, nature accounts, etc., or links to blank empty accounts.  

I think it was pretty foolish of BP to require these links and I have no idea what they were trying to get accomplished by requiring that.

I also notice a very small amount of ads that have no link. Not sure how the advertisers are getting away with that.  

Other ladies are posting in the Massage section of BP, instead of W4M.

Do you see "Ad Boards"?  Ads on TER are free!  

Just be sure to read the Ad posting rules.  

They'll require some info but the ad is free, depending on your area it's a good resource

I used to post an ad on BP once in a while, but yeah, I don't want to fork over a buck every time! That is cutting into my bottom line!!!  LOL
I have also noticed that when I place on ad on CL they are usually pulled within an hour or two, even if the ad is super tame. Pretty much any ad posted by women is pulled right away.  
I have been on Fetlife for a long time and have gotten a lot of clients from there. (It is free) More for the BDSM stuff, but they do have spots and boards that escorts can advertise. They are also super lax on their rules, so you post pretty much any pictures and say whatever you want in the ads.  
When is this country going to give up this stupid witch hunt? There is obviously a need for our services. Legalize and regulate. Ug.  

GOOD LUCK!!!