| GENERAL INFORMATION
The sample includes not only music stores and the music departments at electronics and department stores, but also direct-to-consumer transactions and Internet sales (both physical albums via Internet, and ones bought via digital downloads). A limited array of verifiable sales from concert venues is also tabulated. All sales charts use the entire Nielsen SoundScan panel.
The Nielsen SoundScan system utilizes that same point-of-sale that music merchants use to track their inventory, so an itemized receipt from one's last visit to a music retailer essentially doubles as a ballot cast for our charts.
Certain airplay charts are based on the number of plays that each song received in a given format that week: Mainstream Top 40, Adult Contemporary, Adult Top 40, Alternative, Triple A, Active Rock, Heritage Rock, Mainstream Rock, Mainstream R&B/Hip-Hop, Rhythmic, Adult R&B, Christian AC Songs, Gospel Songs, Dance Airplay and Smooth Jazz Songs. Others are based on audience impressions: Hot 100 Airplay, Rock Songs, Hot Country Songs, Rap Songs, Christian Songs, Hot Latin Songs and Latin airplay charts.
The audience charts cross-reference BDS data with listener information compiled by the Arbitron ratings system to determine the approximate number of audience impressions made for each plays. Thus, a song that plays at 4 a.m. does not count as much as one played at 4 p.m., and a station with a large audience will influence the chart more than either a station in a smaller market or one with a specialized format that attracts less audience.
With few exceptions, stations tracked for Billboard by BDS are commercial stations.
We use both pools of data because while the consumer's decision to purchase is a significant vote of popularity, singles have a job that extends beyond being a sales vehicle: to capture radio play and, hopefully, stimulate album sales.
These two hybrid charts each use formulas to mix Nielsen SoundScan sales with BDS audience. The Hot 100 utilizes the a la carte sale of downloaded tracks with sales of the few retail-available singles that are still shipped to stores. The chart also factors in streaming audio and video data (both on demand and passive) from AOL and Yahoo. The Hot 100 utilizes audience from all popular formats monitored by BDS. The Hot R&B/Hip-Hop Songs chart meshes sales with audience data from R&B and hip-hop stations.
Billboard's Social 50 chart ranks the most active artists on the world's leading social networking sites. Artists' popularity is determined by a formula blending their weekly additions of friends/fans/followers with artist page views and weekly song plays, as measured by Next Big Sound.
Uncharted is a listing of the top new and developing artists who have yet to appear on a major Billboard chart, regardless of country of origin. Rank is based on a formula incorporating streamed plays, page views and fans according to MySpace, as well as sources tracked by online aggregator Next Big Sound, including YouTube, Facebook, Twitter, Last.fm, iLike and Wikipedia, among others. In order to appear on Uncharted, acts must be registered MySpace Music artists and have not appeared specifically-outlined Billboard charts (more than 80 overall).
Billboard's Ringtones chart uses sales data from Nielsen Mobile's RingScan service, which compiles sales information from the majority of ringtone retailers in the U.S. market. The chart ranks sales of master (not polyphonic or monophonic) ringtones.
The Dance Club Songs chart is compiled from reports from a nationwide panel of club DJs, detailing the tracks that elicit the most audience response.
Billboard's Smooth Jazz Songs chart combines airplay data from stations monitored by BDS with those that submit playlist reports online.
The Christian CHR, Christian Rock, Soft AC/Inspirational and Christian AC Indicator charts are compiled from playlist reports that stations playing those genres of music submit online.
THE CHART WEEK
Charts are refreshed every Thursday on billboard.com and billboard.biz and reflect the date of the Billboard issue in which they appear; online-only charts display the same corresponding date.
The printed magazine first reaches newsstands on Friday. Each issue is dated based on the end of its publication week. Thus, the Billboard that reaches newsstands on Friday, March 19, for example, is dated Saturday, March 27.
RULES AND EXPLANATIONS
GLOSSARY OF TERMS
HOT SHOT DEBUT
Songs are removed from Hot Country Songs after 20 weeks if ranking below No. 10 in detections or audience, provided that they are not still gaining enough audience points to bullet or if they rank below No. 10 and post a third consecutive week of audience decline, regardless of total chart weeks.
Songs are removed from Rock Songs, Mainstream Rock, Hot Latin Songs and Latin Airplay charts after 20 weeks if ranking below No. 20.
Descending songs are removed from Adult Contemporary, Adult Top 40 and Adult R&B after 20 weeks if ranking below No. 15, after 26 weeks if ranking below No. 10, or after 52 weeks if ranking below No. 5.
Descending songs are removed from the Mainstream Top 40, Alternative, Triple A, Active Rock, Heritage Rock, Mainstream R&B/Hip-Hop, Rhythmic, Christian Songs, Christian AC Songs, Gospel Songs, Dance Airplay and Smooth Jazz Songs charts after 20 weeks and if ranking below No. 15.
(CD/DVD) after price indicates CD/DVD combo only available.
Pricing and vinyl LP availability are not included on all charts. (EX) after catalog number indicates title is exclusive to one account or has limited distribution.
AWARD CERTIFICATION LEVELS