The reasons that donations via text message are a good thing are also why they’re problematic; it is instantly gratifying, but in that instant, there’s no transparency about the organization receiving funds. Without that knowledge, you could be signed up for a recurring donation, or be giving to a middleman that advocates on behalf of the organization to which you thought you were donating.

from The Washington Post:

Should You Not Donate by Text Message?

We all have our excuses for not donating to disaster relief funds or to our favorite charities: We’re broke, the donation process is too complicated, we lack the time to write and send a check, and so on. Mobile donating – giving money to an organization via text message – makes giving a little easier. But is it safe? And does it have a significant impact on the charity or the people in need?