How does stacking work?

I've also read that NEM can do 4,000 per second.

It's good for staking (harvesting they call it). With a supernode you get 3xx tokens per day.

What's so good about NEM?

2 Months ago, 19th March 2017, NEM's market cap was $150,000,000. (An all time high at the time).

Today, NEM's market cap is $2,300,000,000.

Growth of 14x in 2 months?

Was there some particular news or something?
I've done a little reading on it and it doesn't seem "all that"