Personally, no thank you! I prefer being a monogamous lesbian to being coerced/convinced for economic reasons to engage in activities that hold no interest for me.
That being said, I imagine many girls do it as a means to finance their transitions. It also is a way to avoid the stigma we tend to get in more traditional areas of employment (me go back into teaching? in my state?! Ha!). For others, maybe it's validation that they are pretty or sexy, but the psychological costs I think are too high. If someone wants to do it to finance their tradition, more power to them; however, if they are having to alter their transition plans to enhance their career... it's ultimately a Faustian bargain.