WASHINGTON The Boston radio market fell out of the top 10 in Arbitron's new rankings, effective with the fall 2005 survey (Sept. 22 to Dec. 14). And for the first time, Atlanta, whose population increased 1.9 percent over the past year, moved into the top 10 ranks at No. 10 from No. 11.
The population rankings are adjusted by Arbitron once a year in the fall. Significant changes in population and rank can affect how advertisers allocate ad budgets and how stations are valued for transactions.
Formerly the ninth-largest market, Boston's population fell nearly 1 percent to land the market in the No. 11 spot, seven years after its geographical definition had been expanded by Arbitron. Detroit moved up from No. 10 to No. 9.
Besides Boston, the only market among the top 10 that lost population was San Francisco, which still maintained its No. 4 rank.
With a 5.3 percent increase in population, Las Vegas leapfrogged several positions, to No. 32 from No. 38.
Other notable changes among the top 50 markets include: Tampa-St. Petersburg-Clearwater, Fla., which moved from No. 21 to No. 19. St. Louis slid from No. 19 to No. 20, and Baltimore dropped out of the top 20, from No. 20 to No. 21.
In total, 20 markets among the top 50 changed rank.