[Henke]

Never bluffing is bad IMO. However, the advice to never bluff at microlimits is not that bad to give to a beginner, because 101% of them are usually bluffing to much. If they try to follow that advice they might start bluffing with the correct frequency.

But, there are situations where bluffs might be profitable. For example, suppose the flop is 933 and you're in the big blind. Your four opponents check it around, and you're holding 72o. Your chance of winning here is not very high, but if you bet the turn, you might win more than 2 times out of five. Another possiblity that sometimes arises is when you're on say a str8draw, the pot is big, and on the turn the third suited card falls. If you bet out here (a donkbet) you might win the pot a few times. Notice also that you where probably going to call one bet anyway, and you (usually) won't get raised by other hands than a made flush.

However, the standard bluff of betting and raising overcards on the flop against multiple opponents is often a looser in the long run*. Many opponents think they "know" you have AK when the flop is T32, so they have to keep you honest with mediocre holdings.

*This of course depends on a lot of things, like how big the pot is, your chances of winning if you hit your cards and if you can go for the free card.