Effective CPM represents your estimated earnings for every 1000 impressions you receive.
Effective CPM doesn't represent your earnings - it's calculated by dividing your earnings by number of page impressions, then multiplying by 1000. For example, if you earned $0.15 from 25 page impressions, then your eCPM would equal ($0.15/25)*1000, or $6.00. If you earned $180 from 45,000 impressions, your effective CPM would equal ($180/45,000)*1000, or $4.00.
In your case ...
14 impressions earned you $0.47
.047 divided by 14 X 1000 = $33.57 <--- your eCPM
