[Moss Factor]

Raising on the flop would be less of a bluff to try and win the pot, because so infrequently would someone put a bet out and then fold for 1 a small bet (although it happens occasionally). You'd be most likely raising to get a free card or, depending on the number of opponents you have, for value.

If you have other outs, you'd want to raise to increase your pot equity. For example, if you have Ac2c on Tc6c3d, you'd be raising to try and eliminate other Ax hands, to make the aces outs for you, and also to get out draws like gutshot draws and 3x/6x hands that may make two pair on the turn and lower the chances of your ace being a clean out.

Reasons to not semibluff on the flop would be if you think getting a free card is impossible, you're not getting value from a raise, and you think that the only way to win is to complete your draw.

For example, if you have 67o on a 58K rainbow and you face a bet and a raise. You know with that much agression that putting in a 3-bet is probably not going to slow the action down- the flop will probably capped and the turn bet, so you free card play is useless. Plus you can't raise for value, because nobody behind will call 3-bets cold without a monster, and you're up against only 2 opponents. The way to get value from this pot is to call and try for overcalls to improve your odds. A pair of 6s or 7s probably won't win, and you're going to have to complete your strait to win.

I would suggest calling in such a situation where a raise would not a) give you a free card, b) be for value or c) give you extra outs.