Admob Stats don't make sense

[teynon]

2011/06/09 282,148 1,000 0.35% $40.00 $0.04
2011/06/08 457,396 250 0.05% $10.00 $0.04

I set up an admob account for the first time to try and advertise my
first app on the android market. I set the limit to $10 at first. It
ran out quickly, so I set the next day to use $40. About 1 hour later,
on the 8th, I received a message saying my funds were depleted. ($50
total added) However, this information says that I spent $40 on the
9th.

Copied from Email:
Wed, Jun 8, 2011 at 9:56 PM

The balance of remaining funds for your AdMob account
(tey...@gmail.com) has been depleted.


In addition to that, if you look at the impressions and the click-
through rate, it doesn't make much sense to me. You're telling me that
the first $10 went for almost half a million impressions and got 250
results, but then the second $40 only got 282,000 impressions yet
yielded 1000 clicks. That click through rate is 7 times greater.

Does this make sense to anyone?