Instagram $1 Billion Purchase by Facebook For What?

At the New York Times, Evelyn M. Rusli reports that

Facebook Buys Instagram for $1 Billion

inter alia quoting a Facebook press release as follows:

"Facebook announced today that it has reached an agreement to acquire Instagram, a fun, popular photo-sharing app for mobile devices.

“The total consideration for San Francisco-based Instagram is approximately $1 billion in a combination of cash and shares of Facebook. The transaction, which is subject to customary closing conditions, is expected to close later this quarter."

At the same time at CNN, Molly Wood asks

Facebook buys Instagram...but for what?

Read both articles to get the scoop.