There appear to be different schools of thought on multichannel marketing.

One is that people show channel preference with their initial response. Others believe in the synergy produced by marketing to the same responders using multiple channels regardless of how they were acquired.

One direct marketing forensic analyst believes that channel use is driven more by zip code (i.e. geodemographics) than age. For example suburbia and exurbia prefer online communications. But urbanites prefer direct mail.

And using email or outbound` telemarketing risks alienating donors or any customer unless permission is given.

I hate getting unsolicited calls from anyone. And I get many phone calls from bogus fundraisers. So I insist on direct mail from such suspect callers. Direct mail seems to weed out the fly by nighters. At least, I get an opportunity to investigate them.

So test into multichannel efforts before assuming that it automatically yields a good return. Treat each donor as an individual. And ask for permission to contact them by phone or email. Otherwise, the relationship could sour before it has a chance to grow.