The idiom 'stick your neck out' is typically used in reference to taking a risk by doing something, often for somebody else, that could cause trouble for you, or some other generally negative outcome. The tone used when saying this expression tends to be one of anger and/or frustration, usually directed towards the person you helped. However, it can be used in a positive sense when used in relation to providing motivation or advice to somebody to take more risks. It is very popular, and is therefore common in both a social and professional context. Phrases with a similar meaning include 'put sth/sb on the line,' and 'go out on a limb.'