My rationale is that when someone gives their name they would give a donation as well, but I could be wrong.
I think it depends how it is done.
I once got hooked because by this. I must have given my names to the kollel by Kever Rochel a while ago. I got a call this year from a very friendly sounding woman just simply asking to make sure that the names are accurate, and she went through all the names. Then she asked if there was any special requests, which they would daven for. After the whole conversation, and a number of brachos from her, she added, matter-of-factly, that if I really wanted, I could also help partner with the financial undertaking of the kollel. I was at that point very overwhelmed by her caring call (sounded like an older American living in Eretz Yisroel, who gives really emphatic brachos with real emotion and feeling), and I donated $36 IIRC.