to do sth that is not helpful to sb or that gives a bad impression of them :
You're not doing yourself any favours, working for nothing.
The orchestra did Beethoven no favours.
to do sth that is not helpful to sb or that gives a bad impression of them :
You're not doing yourself any favours, working for nothing.
The orchestra did Beethoven no favours.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005