How much funding have these social media websites taken in, in the order in which they emerged onto the scene?

How much funding have these social media websites taken in, in the order in which they emerged onto the scene?

On average, it takes 23 seconds to type a 140 character tweet; 5 seconds to read one. 

On average, it takes 23 seconds to type a 140 character tweet; 5 seconds to read one.