FB's friend graph is their main product. Everything else exists to enrich the friend graph.
With Giphy, you embed a gif from your Android keyboard and FB recieves your IP and puts a uid on the gif. Just like a tracking pixel, when your recipient views the image FB now has their IP and knows you both communicate. Using the IPs as lookups they can now make a friend suggestion in FB without any activity having taken place in that product.
In reality the fingerprinting is more sophisticated than IP but the idea is the same.
This is not beneath FB, it is the lifeblood of their business. Number of friends is a key metric. They know if they can ratchet that number up then you will use the platform more. Which is why they paid so much for Giphy which otherwise has no business model or path to profitability.
With Giphy, you embed a gif from your Android keyboard and FB recieves your IP and puts a uid on the gif. Just like a tracking pixel, when your recipient views the image FB now has their IP and knows you both communicate. Using the IPs as lookups they can now make a friend suggestion in FB without any activity having taken place in that product.
In reality the fingerprinting is more sophisticated than IP but the idea is the same.
This is not beneath FB, it is the lifeblood of their business. Number of friends is a key metric. They know if they can ratchet that number up then you will use the platform more. Which is why they paid so much for Giphy which otherwise has no business model or path to profitability.