Progressive meter "bump"

I was playing a bank of 10 machines .25 deuces wild progressive with the meter at $1180 or so. Few people were playing at the time, so the meter inched up slowly during the course of an hour's play. When it got to $1198 I left for lunch, came back an hour later, and the meter was now at $1780! None of the players who were playing when I had left were still there, but one of the newcomers said "I bet that they bump up the progressive in order to get more play." If so, it indeed worked in that almost all the machines were now full. I've never witnessed anything like this before. Is this commonplace?

Sometimes one progressive jackpot is discontinued and the money gets dumped into/consolidated with another, for whatever reason. I saw that happen with Megabucks once. I forget the details, but the jackpot suddently jumped up by several million. I don't know how commonplace it is.