What eupho said. Not sure if you play cash or tourneys, but in tourneys you can have seriously bad reverse implied odds by playing marginal hands out of position when it costs you a lot of chips to find out you had the losing hand.

Here's an example. Early in a 1-table SNG, full table, stacks all around 1500, blinds 15/30, you're dealt A T UTG+1 and UTG folds. You decide to raise to 120, CO calls and the blinds fold. The pot at this stage is 275.

Flop comes A J 5. You bet 180 and CO calls. The pot is now 635.

Turn comes 5. You check, CO bets 200, you call. The pot is now 1035.

River comes 7. You check, CO bets 250 and you have to call getting better than 5:1 odds and he shows you AQo.

So, even though you only raised to 120 preflop it cost you another 630 chips even though you didn't play that badly postflop because you couldn't let go of the second best hand. A LOT of bad players would lose their whole stack in this spot.