More clicks, more eCPM, same earnings?

[Fryman]

This has happened to me 2 times now in the last few weeks. Just inventing figures to not violate the TOS: one day I have 386 clicks with a ecpm of .51 and earn $51.38, the next day I have 498 clicks with ecpm of .87 and earn $51.45

Why does this happen?

[elsewhen]

all of those figures are consistent. eCPM is a calculation of the amount of money you are getting per 1000 (M) impressions; it is not based on clicks.

your examples did not provide the number of ad impressions.

the day you earned $51.38, you must have had 100,745 impressions. (100.7 x .51 = $51.38)

on the day you earned $51.45 you must have had 59,138 impressions. (59.1 x .87 = $51.45)