tangor - 1:42 pm on May 10, 2009 (gmt 0)
I do not followup on insufficient funds declines. There might be good reasons why it was declined. Usually wait until those customers come back with sufficient funds. Otherwise that's flogging a dead horse and might make for an embarrassed or unhappy customer. Failing to complete the cart, on the other hand, is something you do follow up...and track the errors to see if modifying your cart will REDUCE those errors.