Ask HN: Entrepreneurs, how do you get introductions from investors decline?

I'm currently raising money from investors for my revenue-generating startup. I've reached out to all the angel and VC investors I know, and whenever someone declines, I ask for introductions to other investors they know - this process has resulted in exactly zero introductions.

This morning I heard from angel investor David Cohen, to whom I had sent my executive summary "over the transom" (I don't know David and had never been in touch with him prior to sending him my exec summary) - he had said it wasn't a fit, so I asked for introductions as usual. Here is what he said:

     I can't do referrals - they'll just ask why I'm not investing and it won't help you.

     brad feld has a good post on why -> http://www.feld.com/wp/archives/2007/11/dont-ask-for-a-referral-if-i-say-no.html

     i am always happy to look at potential deals. thanks.

(That third line was in response to me asking if he'd like me to introduce my entrepreneurial colleagues to him when my colleagues are seeking funding - by the way, though David wasn't interested, I very much appreciate his welcoming of executive summaries, and his quick replies - if you are raising money you should contact him)

Brad Feld's article summarizes why David Cohen, Brad Feld, and presumably most other investors will not make introductions to other investors for deals they decline. I didn't realize that this "no intros if I'm not interested" policy was so widespread.

Thus my question: have any of you entrepreneurs been successful in getting introductions from investors who decline your deals? If so, how did you accomplish this?