I agree with Emmett on being realistic. It's also important to be transparent. I'll set expectations right on the sales call, or even the "discovery" call if one is necessary. This way there's no surprises, no saturday afternoon texts, no jumping ship after 2 weeks because "our phone isn't ringing". For me, focusing on on being as upfront and as transparent with results as possible from the start makes the selling easier, makes it easier for delivery, and the clients are happier when they start seeing results. Don't forget - under promise, over deliver.