Second, I worry that people won't give as well. I'm a firm believer in fewer, larger donations to organizations that you really know. Are you likely to research an organization before shooting off a quick text? My guess would be not very. Case in point: Grammy-winning musician and Haiti native Wyclef Jean's Yéle Haiti charity came under scrutiny due to accounting irregularities soon after the quakebut still managed to raise more than $2 million via text messages within two days of the disaster. So it's reassuring to do your research beforehand and give to a charity you trust.
While disaster giving may not be included in your annual giving plan, it doesn't make it any less important. Your donations are limited no matter who you are, so make sure that they are going to the organization with the most capacity for impact—whether it's via text, PayPal, or courier pigeon.