jyms posted a WHY post in his op/blog a while ago.
That's what I ask myself at the moment.

Quote Originally Posted by BooG690
Do NOT fall into the trap of playing sub-par hands just to enter more hands with a fishy villain. Widen your range...but be weary of becoming reckless!
assuming a passive fish who is limping.
Isolate with an appropriate range - why/why not A6o? how about 89s?
When/why to limp behind? what sort of hands?
Watch out for squeeze type players behind though. Learn about his pre-flop response to isos. Know when to c-bet, when to check behind. Stack him. Do it again.