Apparently a few large followed accounts follow me that I wasn't aware of, neat application... An idea I've wanted to do for a long time (but isn't technically

Apparently a few large followed accounts follow me that I wasn't aware of, neat application... An idea I've wanted to do for a long time (but isn't technically possible) is to analyse the reach a user has. For example, when I tweet normally it is sent out to my ~520 followers, but what about when my tweet is retweeted? What about how many are active and the chances that they saw the tweet? It would be really interesting to see stuff like that. Side note, can you explain "VIP Factor?" I assume it's where you position in their follows (longer that they've followed the higher the score)?