I take it back, then. I assumed that it would be pointless because nobody is keeping track of it any more to even know it's free, but I was probably wrong.
Would such an outcome also be possible from existing players simply playing for longer, hence more over-lap with other players logging in and a larger peak? For example, if 10 different people logged in every 10 minutes and only played for 5 minutes at a time, after an hour it would only have a peak of 10, but if they stayed for an hour then 60 would show.
But then I guess if separate logins are counted, only crashes would explain an increase of re-logging in, but more actual players makes more sense.