We deal with this sort of thing all the time. The best move, I think, would be to be very upfront about how competitive the particular market is and your though

We deal with this sort of thing all the time. The best move, I think, would be to be very upfront about how competitive the particular market is and your thoughts on that. And be VERY clear about the scope and what he's getting from you. onion2k is right - when he's not getting the traffic he imagined, you're gonna be on the hook for the "fixes" necessary to make that happen.