Reminds me of the old saying —don’t buy the cow if you can get milked for free (I’m paraphrasing here).
Personally, from guys only advertising on massage sites I’ve had some massages turn into a full escort service, massages ending in a little mutual touching and HE and massages providing pretty decent muscle therapy . . . all for the massage rate. I don’t expect “full service” or a “boyfriend experience” from someone advertising only on massage sites, and am typically content with a decent massage, something pretty to look at, and maybe a few sensual elements. It’s a nice treat if more happens (and if I’m into it as well). Moreover, I’m typically too shy to make the first moves with someone I’ve never seen before, so in just about every instance what happens during the massage session has been instigated by the provider. I guess it’s a two-way street.