[NSM]

Chi, this may or may not be a +EV play out of context, but for me it is something that helps me assign a style to my opponent early in a match with no other information. I know that I will check/call opponents all 3 streets as well OOP if i flopped middle or bottom pair (or have an unimproved but not crushed PP). However, I think pot sized bets from the button on the flop make this easy to do. If I make it 90 into a limped pot of 60, I'm making a check/call strategy that much more expensive for my opponent and also maybe inducing a check raise earlier in the hand that tells me a lot about what they flopped (ie, now I'll stop betting w/ my top pair weak kicker or middle pair).

If I flopped top pair, I'm getting a lot of value from their check call on all 3 streets w/ middle pair.

If I flopped air and they call I could be done or I could doublebarrel and get more from them than they intended to give by calling w/ bottom pair or some gutshot draw on the flop. At least the threat of an expensive turn and river are present and my CB's start to get more respect from bottom pair, etc.