By first registering for the promotion and then completing one of the designated activities, you are earning “green” credits for your city. The more actions you take, the more credits you earn, up to the limits shown. Throughout the day, we will add up the credits for your city – based on the 5-digit zip code you registered with – and will compare those to the population of your city to determine the “greenness” of your city.
| Activity | Credits |
| Pledges Submitted | 100 |
| Best Answers Received in the Environment Category | 75 |
| All Other Best Answers Received | 10 |
| Mobile oneSearches Completed* | 10 |
All cities with four or more registrants who have each completed at least one designated activity will be eligible to win. Total credits will be weighted based on each city’s population. City population is based on 2005 census data, as found in the “American FactFinder”.
| Population | Weight |
| 2 million residents or more | 1.0 |
| 100,000 – 1,999,999 residents | 0.856196464 |
| 20,000 – 99,999 residents | 0.782958516 |
| 5,000 – 19,999 residents | 0.431191027 |
| 2,000 – 4,999 residents | 0.176672814 |
| Fewer than 2,000 residents | 0.053420396 |
In short, ((Total Credits/Population)*1,000)*Weighting = Your City’s “Greenest City” Score.
It may take a day or two for credits from the designated activities to appear on the “Greenest City” map and to affect your city's ranking.
Please note that even if a particular city is listed as the "Greenest" as of the end of this promotion, the results shown on the map are unofficial and are subject to verification before a winner will be determined. The winning city will be announced on June 19, 2007.
* A Mobile search is completed after the search is done and the user has clicked the link to get their free CFL and entered their Yahoo! ID.