Yes, some days pay better for everyone. That's one reason why it can be a big difference.

The activity level of your reader makes a difference too. Someone really active might give out two cents while someone not as active can give out $2 for the same amount of engagement.

Also, the earnings are sometimes delayed up to two days for new articles.

So, factor in all of these different scenarios and it's easier to see why earnings don't make a lot of sense because it's too many variables.