As a part of the financial regulation overhaul, many banks are implementing changes to their overdraft rules such as the news out of BofA today. http://news.yahoo.com/s/ap/20100310/ap_on_bi_ge/us_overdraft_fees_bank_of_america
While it will be difficult to know if there will be much impact from this on ecommerce sales for either one time purchases or recurring payments, it is something to at least be aware of.
As this article states, for at least some of their customers, BofA was allowing transactions to proceed even if the consumer's account was over the limit (for credit cards) or out of money (for debit cards).
