While not everyone can withstand the temptations of having $3 billion in their bank account, Snapchat is the very rare startup that just rejected Facebook's all cash buyout.

The two year old app lets people send photos to friends that vanish in 10 seconds or less after they are opened. The app has no revenue. They have super growth and incredible engagement numbers.

Here are the reasons why Facebook wanted Snapchat:

• Sharing photos is the core use for Facebook. Snapchat is fast becoming one of the biggest photo sharing applications on smartphones.
  
• Snapchat is developing a unique "social graph". Facebook's whole thing is about understanding the social graph, or how we interact with our friends. It's missing out on a new, key set of social data as Snapchat grows.
• "Facebook-nevers" are going to Snapchat. Teens look at Facebook how adults look at LinkedIn. It's not super cool, and it's not a place to let it all hang out. All the kids are going to Snapchat.
  

Snapchat also provides a safe haven for people. Whatever you post online, won't remain online. So if you commit a faux pas, you're quickly forgotten in 10 seconds.

No word on whether Snapchat rejected Facebook's offer in 10 seconds though.