For single posts, I'd say resist the impulse; it adds noise to the discussion and rarely helps anything. If the error is repeated, then it may be more helpful to correct.

Mainly I think we try to just lead by example.

The OP used "loose" twice in his comment. My post was to point out his mistake without being snarky. Obviously, some people think otherwise.. sigh..

Some spelling/grammar corrections are irrelevant, abusive, and inflammatory while others are instructive, helpful, and interesting. This community (to me) is more about the "hey, did you know that it's 'capital' except for when you're talking about the building, then it's 'capitol'" than the "STFU stupid, u can't even spell right"