The fee structure for "credit" purchases is different than that for "debit" purchases. It's in the interest of VISA to have me run the transaction as "credit". Would it surprise you if there was cooperation between BoA and VISA (or any other CC provider) to encourage the use of this? The $5/mo charge just encourages it even further.
You're absolutely right, the structure is different for Signature and PIN debit. Pre-Durbin there was a large gap between Signature and PIN debit interchange income and banks wanted you to use Signature debit for that reason.
With Durbin rules implemented that gap has narrowed and now the bank wants you to use an actual Credit Card vs. a Signature Debit transaction because they will make more interchange income off of it.
The fee structure for "credit" purchases is different than that for "debit" purchases. It's in the interest of VISA to have me run the transaction as "credit". Would it surprise you if there was cooperation between BoA and VISA (or any other CC provider) to encourage the use of this? The $5/mo charge just encourages it even further.