I have a DAF myself, and really love the way it separates the tax event [donating appreciated stock] and the donations to specific charities. But if it was all just about cash from my checking account, I'm not sure I'd find it worth the bother--I'd just mail checks to the charities directly. Once you can do regular automatic deposits, whether from payroll or from a user's bank account, I think it becomes a much more compelling service. I do hope you get there soon.
I do see that the gift-matching part can make it a valuable service even so. I look forward to your taking on Benevity for the gift-matching part; I've found their service and customer support to be rather poor.