Business Insider reports that Chicago-based Groupon has acquired European competitor Citydeal. The online social networking shopping site (I guess that’s how you’d describe it) now has 900 employees – 600 joining as part of this deal – and is live in 18 countries. And they’re now valued at over a billion dollars. They’ve been in business for 19 months. And they’re the winners of the prestigious If I’d Have Thought Of That I’d Be Rich Now Dammit award.