  I just responded elsewhere to a discussion re a service submissive and whether her offer to clean house and then go away, no strings attached, was legit. It was striking to me how many people instantly bristle at the idea and say outright that they suspect ulterior motives when they hear such an offer. I think for a large portion of the D/s world, particularly those used to playing in SDDs (scene-delimited D/s) encounters where the quid pro quo is obvious, such a service offer without obvious exchange value looks odd, even unbelievable. But I am put in mind of various people of my acquaintance who are most excellent and dedicated service submissives, who go into a virtual zen state of "chop wood, carry water", and putz and schlep and do until the task is done - and that, in and of itself warms the cockles of their hearts. Add to that, doing this service for someone they like and respect (much less love or have a crush on! ;) - and they are in hog heaven. While I also have known many submissives who have concocted service scenarios as a (rather obvious) way to worm their way into association with a dominant, these other, truly service-oriented subs *do* exist, and I think are priceless gems. It is unfortunate that people see that espoused attitude and become suspicious of it, when a little dialog, IMX, is sufficient to determine where the person is really coming from. Besides, I wouldn't engage with anyone that way unless I enjoyed their energy to begin with. But if so, it could be a mutually fulfilling relationship.
Maybe at the heart of this suspicon factor (ie, "what are you getting out it?!? ") is a lack of attunement to the exchange the service submissive perceives they are getting. The service IS the quid pro quo. Maybe I need to write something about this at essay length and put it on my website (currently under revision). There's a lot to say about exchange value and equity that is really spot-on in this discussion. Bottom line, though: I think it's easy to screen out the boneheads, but it is also too easy to dismiss the true service-oriented submissive when the Dom/me is not attuned to the quid pro quo in the pure-service dynamic. And that's a loss. 
