His $10.40 is the cost for an "incremental" 4-top, ie a group that wouldn't have booked without coming in via opentable since they were new to the place. Give

His $10.40 is the cost for an "incremental" 4-top, ie a group that wouldn't have booked without coming in via opentable since they were new to the place. Given that even OpenTable's info estimates only 50% of the bookings would be incremental, and that that's likely an overestimate in OT's favor, I can imagine $10.40 may be about right. 4-top via OT = $4 1/2 4-tops from OT "incremental", cost is now $8 per incremental. If it's really 2/5 4-tops from OT are incremental, we're at $10 per incremental.