Basically everyone seems to advice against limping in, and I do get the logic behind it (or at least I think). But currently my goal is to make a little bit of money at the microstakes and there it often seems beneficial to limp in (currently I only played for play-money at the lowest possible stakes, but I assume people at the microstakes play roughly the same).
The problem is that raising with a good hand doesn't cause people with bad hands to fold, and on the flop they often improve their hand. Moreover, since people often play with bad hands, I recently started to limp in with mediocre hands, hoping to get two pairs or three of a kind. I then raise slowly and only at the end (when I hope someone has a high pair) I raise really big and people with a high pair usually call. This also goes in against the advice of not slow-playing. Basically I believe that limping in at the microstakes is good because making two pair (even if the pair are low) is already quite a lucrative hand at the microstakes, but you don't want to risk a lot of money making these two pair (and often all other players limp in as well, making this strategy possible).
It seems to me that this is quite profitable, but it goes in against literally all advice I have read so far. If I would have followed the common advice of not limping, I would have missed out on a few really big pots, while not saving that many big blinds.
So why is everyone against limping? I would like to clear this problem up before I go to the real-money microstakes.