[Randiek]

A lot of players use the 4bb+1bb per limper as a rule for the size of a preflop raise.

However, if a person does this a lot you could indeed limprr him, but I don't think this will happen alot. Mostly because you have to have 2-3 limpers and no raise, which is not something that happens a lot at the site I play at. I don't ever like limping in after other limpers with big hands because you really need a sick read that the BB will raise with any hand, or else you might have a problem when he just checks and you are on a random flop with 5 players with AA.