Im nearly certain there was an excellent TPC comment in that conversation that was not included in this post, but I'll go with it because I like these:

What's an example of when you should 3bet but you call instead?

80/3 villain who loves to fold to cbets, limps UTG and the CO raises to 5x bb, I'm OTB with KK and I call rather than 3bet to get Mr. 80/3 to come along for the ride and fold to my cbet on the flop.