At its core, Facebook is a photo-sharing company. It's enhanced by other features such as status updates and shared links.

To be the ultimate social site, Facebook needs to be the best sharing platform out there for all types of media, including articles, photos and video.

Twitter has proven to be a worthy competitor. It's arguably a better source for social news and link sharing despite having fewer global users. Its video product, Vine, has been gaining in popularity while Facebook lacks a good video solution (although Instagram may be launching a video product on Thursday).

The only thing Twitter is missing is a powerful photo tool. It tried to secure one – Instagram – but Facebook smartly blocked the sale.

In a recent interview with PandoDaily's Sarah Lacy, Union Square Ventures investor Fred Wilson discussed how "genius" it was for Facebook to acquire Instagram, especially because Twitter's Jack Dorsey made an offer first.

"If [Twitter] had Instagram they would be better than Facebook," Wilson told Lacy. (Disclosure: Wilson invested in Twitter). “They’d have tweets; they’d have photos; and they’d have videos. And I think that would be the trifecta that would kill Facebook.”

Here's the clip: