First of all, I am known for my own propensity for writing long posts on here. A sorta mia culpa which I am acutely well aware of. That said, I tend to write only about three paragraphs and each is limited to like 2-3 sentences at most when I send an emal on SA to a prospect:

After opening with the customary Hi / Hello and hope that you...

The first paragraph tells them as to what piqued my interest about them indicating that I actually read their darn profile and that I'm not doing some sort of grotesque one liner carpet bombing!

The Second paragraph draws their attention to my profile and state briefly as to why I think we maybe compatible and I suggest sharing photos if / when I hear back (I don't usually share my private photos  right off the bat)

The last paragraph is about what I'm looking for in a "beneficial" relationship. I do not mentioned any number$ but I do strongly hint as to I know what these relationships are supposed to be all about and that I'm not a time waster!

Then I close with something like: BTW, my name is "Chubby" or something like that. Never, hope to hear from you soon, eager to hear from you, blah-blah... Never show desperation!

Lastly, if I am really really interested in someone who has checked my initial email but never wrote back; I will hit up with a follow up 4-5 days later (depending on how often I see them active) and tell them something like, "I know how some girls get inundated on SA with emails so I wanted to jump in front of the line of your potential suitors"... Blah, Blah...

There will never be a third time! Feel free to use if it bodes well with your style.