Recently, Will Schmitt of Classy posted a blog discussing the limitations of text to give and text to donate services (he distinguishes the two). The blog does point out some interesting considerations, but it overstates the limitations of text to give.
One would think that a recession would make people more tight-fisted. But IRS data shows the opposite. For example, during the Great Recession, individuals and households dug down deeper and contributed more to charity. Even though there was a sharp decline in both household income and household wealth from 2006-2012, there was an uptick in charitable donations of 2.7% during this period.
Retaining donors, getting them to come back again and again to give, is an essential element in growing your revenues and donor base. If you want growth, focus on donor retention.