They almost certainly have trillions of rows of data. The popular social media / user-generated content sites are just huge. You can easily get to that size just from the core product OLTP data/metadata, no need to include media.
For one comparison, Tumblr hit 100 billion unique rows of relational data in MySQL (on masters, not including replicas) back in October 2012. So they're easily in the trillions of rows today, and Tumblr is smaller than Pinterest!
For one comparison, Tumblr hit 100 billion unique rows of relational data in MySQL (on masters, not including replicas) back in October 2012. So they're easily in the trillions of rows today, and Tumblr is smaller than Pinterest!