Network TAPs provide the details that Span ports Don't

NETWORKS ARE GROWING FASTER THAN EVER
In 2016 Gartner estimates that there are 6.4 billion connected things, with that number expected to grow to 20.8 billion by 2020. This means exponentially more and more complex traffic
When complexity goes up, visbility needs to go up. You need to see everything in your network
When it comes to visibility, your first line of defense is access to data
You have two choices: TAPs or SPAN