If you think your "brand" is something marketing people construct, you're missing the point.
Check out this short video from Brand Autospsy on "talkable" brands:
(Or see it here on YouTube.
A brand is a reality that people experience, not a set of communications guidelines. Of course, your communications should support, not get in the way of, what people are experiencing -- but unless the reality your donors experience is really excellent, you hardly have a brand people are going to talk about.
If your donors are not the same people as your beneficiaries, this means:
- Thank them promptly and powerfully.
- Report back consistently on the impact of their giving.
- Make sure the connection between their giving and your cause is always clear.