On the flip side, I made my first reservation through opentable a few weeks ago, and I was surprised when they DIDN'T ask for any cc info. Granted I was new to the experience, but the first thing that crossed my mind was I could not show up and it wouldn't be a big deal.
Feel like if they market this move a little better, they could convince their loyal customers that this will allow them a better chance at getting reservations.
Only very popular restaurants require a CC on OpenTable. One of the nice things about OT is that it's very easy to cancel (one click) which I suspect also helps restaurants maximize their yield, since they don't have to keep a table open for a reservation that never shows up. Taking a CC may discourage some people from making a reservation so if you're not already at capacity, it may not be a good play.