Used other than figuratively or idiomatically: see guess, what.
(idiomatic, by ellipsis, rhetoric question) Used to introduce a surprising outcome or one that the hearer is not expected to try to guess.
(idiomatic) Used to dramatize the introduction of an unsurprising outcome.
I've only had two job interviews and – guess what – no job offers.
Dancing is a wonderful training for girls, it's the first way you learn to guess what a man is going to do before he does it. Christopher Morley
I guess what people forget sometimes is that when I write songs, I write them sometimes in about 20 minutes. Alanis Morissette
If you don't design your own life plan, chances are you'll fall into someone else's plan. And guess what they have planned for you? Not much. Jim Rohn
A month passes by and brings another month. Easy to guess what lies ahead: all of yesterday's boredom. And tomorrow ends up no longer like tomorrow. Constantine P. Cavafy
Arrested Development opened a lot of doors for me, and once I sort of became, I guess what you'd say "available," there was a lot of opportunity out there, and it's been nice; a lot of people have found it in their hearts to offer me movie parts. Will Arnett
I guess what I'm trying to say is that you are there, in everything I am, in everything I've ever done, and looking back, I know that I should have told you know much you've always meant to me. Nicholas Sparks