The decision by CBS Radio to acquire an FM channel for All News 740 KCBS seems to be paying off. KCBS AM-FM was first in the January Arbitron ratings for listeners 6+ with a 6.4 rating compared to 5.8 for perennial leader KGO-AM.

A year ago, KCBS (which had just started its FM service) had a 5.6 compared to KGO’s 5.8. In one year, KCBS has grown its listenership by 14%.

Here’s the usual disclaimer: Advertisers don’t use these numbers when buying air time. They use ratings for particular demographics.

PPM 6+
          San Francisco Radio Metro
         Monday-Sunday 6am-Midnight
               Jan 09   Dec 09   Jan 10
1.  KCBS-AM/FM   5.6      5.8      6.4
2.  KGO-AM       5.5      5.8      5.8
3.  KOIT-FM      4.8      5.4      5.7
4.  KQED-FM      5.3      4.8      4.5
5.  WILD-FM      3.4      3.8      4.0
6.  KBLX-FM               4.0      3.9
7.  Star 103.1   3.6      4.1      3.9
8.  KNBR-AM               3.6      3.5
9.  KSOL                  3.4      3.5
10. MOViN 99.7            2.8      3.5
11. KDFC-FM               3.4      3.2
12. KRZZ                  3.2      3.2
13. KMEL-FM      3.7      2.6      2.9
14. KSFO-AM      3.3      3.1      2.7
15. KISS-FM               2.5      2.5
16. KFOG-FM               2.4      2.4
17. KSAN-FM               2.0      2.3
18. KBAY-FM               2.7      2.0
19. The Band              1.9      2.2
20. Alice                 2.4      2.1