Thanks Alex. We offer Dwolla as offsite payment provider (for members to pay their bills online) but I wasn't aware they supported ACH.
It is indeed a question of perception. Technology, at the end of the day, is a matter of finding the right partner/tool and typing the right code, but if applied in the wrong context, it will just not make things easier.
Answering your question, in the UK for example, Direct Debit (the closest process to ACH) is widespread. Most people pay subscriptions, utility bills, accommodation, and the like using this method.
Personally, as a payer, I rather use my card, pay there and then, a not have any authorizations laying around. But from the perspective of someone running a space I can see how, given the right transaction volume, those %s add up quickly. So yes, I guess it all depends of the size, the users and how the whole process is implemented and perceived by them... very interesting topic and definitively a lot of food for some lateral thoughts and original solutions...
Adrian