" For a continuation bet to be a profitable move, the amount of the bet has to be carefully chosen in comparison to the pot. In essence, you are hoping to buy the pot right now. If you overpay, you'll lose too much money when your opponent calls with a hand better than yours. If you underpay, you'll be offering your opponent correct pot odds to stick around with a drawing hand. Neither situation is good, so the exact amount of the bet is very important. "

― Dan Harrington , Harrington on Hold 'em: Expert Strategy for No-Limit Tournaments, Volume I: Strategic Play