Boston
I think it is possible if the conditions are right.
Both parties would have to agree on ground rule of how this would work. Most important is if non of the parties involved break the rule. Now how many times have you heard of that happening.
I think we all have our ATF's and when we want to have a good time and not deal with any drama. These are the women we go back to see again and again.
But were all dogs and we will always be sniffing around to see what is out there
Yes...
It's called a Sugar Daddy type relationship or a relationship with benefits. Unlike the kept mistress, in this relationship the woman is reserved for an agreed upon period of time each week. She is allowed to live her life as usual, but commits to being available for the gentleman as per agreement.
I believe many providers who have been on the scene for a while have had at least one, if not many of these relationships. They are mutually beneficial for both parties.
Take for example a newly divorced man. He wants to have fun but he probably is not ready to jump back into a mainstream relationship, especially if the divorce wasn't dissolved in an amicable fashion. He may see a few escort ladies, and take a liking to one that he eventually has visiting with him weekly. This can go on for months or even years.
Often these relationships bring the lady into the gentlemen's personal life for periods of time such as companionship for business events and company for attending the theater and for fine dining. It's more fun knowing you are going to get very lucky at the end of the night than playing the dating game. (In fact many men find these arrangements more cost effective)
Unfortunately, like all good things it will eventually have to come to an end. Sometimes the gentleman gets too serious and the provider is not interested, and it is time for him to move on in the real dating scene, other times he just needs a change. And sometimes they marry, if you can believe that! Of course, I am just answering your question, therefore I am not admitting to being a part of any of these scenarios. 
In my brief scan of the responses you've received, Nicole hit the nail on the head. Some men just want someone they can trust and feel comfortable with that will not push the relationship to the next level. The lady makes out, the man gets better taken care of then he ever would in a typical relationship so it's a win-win. And yes, there are arrangements such as this which are 'Don't ask-Don't tell' as long as the lady is available for the same time frame each week.
I guess a simple Yes would have sufficed, but as some of you gents know if you're not kissing me or sticking your balls or cock in my mouth I might just be a little verbal-Ooooooh Baaaaybbbbee!
Kate xo
I don't think an incentive program works for that sort of relationship: it is one that evolves over time.
It seems that all hobbyists have their ATF's and it depends on the tastes of the hobbyist.
Bottom line is, no matter, enjoy, enjoy one provider, or enjoy them all 