Is 'why wait?' a correct usage?
I need to write a short tag line for an ad. 'Why do you have to wait?' is too long. instead can we use 'why wait?'
Certainly you can. There are similar constructions such as Why worry?
In fact, the candy bar brand Snickers has a well known ad campaign with the slogan "Hungry? Why wait?" meaning, "Are you hungry now? Why should you wait until later to eat?"