While somewhat humorous, I think you all are being a bit harsh. I'm as curmudgeonly as anyone else born in the '70s, but why begrudge a company whose age can be measured in weeks having a tremendous windfall?
It appears a young company launched with a great user experience, and great engagement metrics. They got a premium for that. The deal terms aren't public, but we know it was a mix of cash and equity (probably skewed toward equity).
Didn't the founder of SnapChat turn down a ~$15B+ offer? I think this company will be a major contender in social media.