CNET wonders why Facebook spent $1billion on Instagram

I didn't know what Instagram was until I visited my daughter who is a bartender in California. One of her friends, sitting on a bar stool, snapped her pic with her iPhone and instantly it was on the Net for me to see as I sat a couple of bar stools away. She uploaded it on Instagram right from her iPhone.
 Today's news is that Facebook bought Instagram and a CNET editors muses about why:
"There's a lot of speculation today about why Facebook would spend $1 billion to acquire the uber-hip photo-sharing app Instagram. To some, it seems obvious; to others, it's the biggest sign yet of a growing Web bubble. To me, it just raises question after question, and the biggest one is "why." What does Facebook gain from buying Instagram? Let's look at some of the possible reasons, shall we?"
You can read the whole column here 
I don't know any more than the columnist but I can testify that the young hip California people are into it. Maybe that's all it takes. (PR)