Data tends to accumulate next to other data.

Because crossing origin boundaries is hard, all else equal, data tends to accumulate on the side of the boundary that already has more data.

More data within a boundary means more option value and potential (the potential value of data rises with something similar to the square of the data).

Also the side with more data has more heft, more power to compel the incremental data to come to their side.

In a conversation this week someone called it "data gravity" which somehow I had never heard, but I love.