Tracking conversions

If you place referral ads on your page, you’ll want to also track how they’re
performing. AdSense gives you some tools to do that. After you set up your
AdSense referrals, a new report becomes available in the Reports section
of your AdSense account. Right there on the front page is the new Referrals
report. If you click this report, you’re shown some stats based on the performance
of your referral ads.
For each referral ad you display, you see the following stats:
Clicks: This number indicates every time that a site visitor has clicked
your referral ad even when a conversion doesn’t follow.
Sign-ups: When a referral product — like AdSense — requires a sign-up,
and your site visitors actually do sign up, that number is displayed in
this column.
Conversions: When your visitors click through your referral ads and
complete the required conversion, this is where that fact gets recorded.
Conversions are listed by product.
Earnings: Here’s the line that interests you the most, I’m sure. This line tells
you exactly how much you’ve earned from your referral ads, by product.