The infomercial
Are you following me son? If you eat 2 bites of spaghetti now I can offer you—at no additional cost—3, count 'em, 3 plump red grapes. But wait that's not all, if you eat all the food on your plate—that's the spaghetti, the bread, and the carrots—you will receive, at no additional cost, the grapes AND this chocolate chip cookie! All for the low, low cost of 10 bites!
The used car salesman
Sir what's it gonna take to get you to poop on the potty? It not only comes with the satisfaction of us knowing we don't have to change any diapers anymore, but we'll also throw in a bunch of extras just for you: a new train for your train set; a trip to Chuck E. Cheese's; and a trip to the toy store to pick out anything you want. And don't forget about the ladies, ladies love a guy who can poop on the potty. Make me an offer and I'll check with you mother and we'll see if we can't make this happen.