This is missing a HUGE aspect of intro etiquette - DOUBLE OPT-IN, almost all the time (and if you aren't sure, then it's ALL the time). If you want your contacts to be worth something, be respectful of them.
Here's my "workflow"
1. Intro request comes from Bob who wants to meet Jim
2. I review Bob's email, make sure it's short and to the point, and includes WHY it's a request. If I don't think it hits the money, send feedback and recommend edits to Bob. Wait for acceptable email - which must be its own, NEW & clean email. [edited for clarity: i inform Bob that I will send him whatever he writes to Jim, thus allowing him to position himself/his need/the opportunity in his own words]
3. I forward Bob's entire good email to Jim, which includes MY take on the matter (I think Bob's a great guy, or I am not familiar with Bob's company, but we've worked together before and he's worth meeting, or whatever).
4. If, AND ONLY IF, I get a reply from Jim agreeing to the intro, do I continue forward. But if Jim says he doesn't want the intro, I politely decline back to Bob.
Personally, I hate it when someone dumps an intro in my lap - it just isn't courteous or respectful in my opinion.