Do you expect your customers to know stuff they clearly don't? If so you're not the only one. See what one large company did.
Every time I think about this, it makes me laugh until I cry, particularly when you look at the pictures. It's someting online fashion giant, ASOS got terribly long (sorry, wrong!… http://queenofprofit.co.uk/blog/2016/10/how-long-too-long/