What does a gravity delta mean?

A gravity delta is a difference between today's gravity and gravity N days ago.

For example, today a vendor's gravity is 500.17. And 30 days ago it was 318.85.

The 30-day gravity delta of this vendor is equal to: 500.17 - 318.85 = 181.32.

If we order vendors by their gravity deltas we can find those vendors whose gravity has been highly increased. In this way we can discover ClickBank Movers.