I found it very interesting this week when a client said to me, “Aren’t most of the TV networks about the same? I watch them all.”

I told her that she may watch them all, but the ratings tell us another story. The ratings this past week told us that CBS wins big in household numbers, and in the demo of Adults 18-49,  Fox is the leader.

When buying TV it is very important to know the “numbers.” You are not buying number of spots, you are buying “people.” You need to know how many people. You need to know the “share” you are getting and the age and gender of the “people” you are reaching.

For example, according to a publication we subscribe to called “Spots and Dots” CBS got a huge victory in HHs (households) on Tuesday, but a new episode of Glee moved Fox ahead of CBS in A18-49 (adults) in Nielsen’s overnight markets. In HHs, CBS averaged a 10.6/16 to Fox’s 6.1/9, NBC’s 4.9/8, ABC’s 3.5/5 and the CW’s 1.3/2. Fox got a 3.4/9 in the demo, edging by CBS’ 3.3/9. NBC drew a 2.6/7, ABC a 1.5/4 and the CW a 0.7/2. NCIS began CBS’ night with a 12.6/19 in HHs and a 4.2/12 in A18-49. NCIS:LA followed with a 10.7/16-3.5/9 and The Good Wife earned an 8.4/14-2.2/6. Fox drew an 8.2/12-4.5/12 with Glee. Raising Hope was a 4.6/7-2.8/8 and Traffic Light premiered to a 3.4/5-1.9/5. The 2-hour Biggest Loser Couples delivered a 5.8/9-3.0/9 for NBC and Parenthood got a 3.8/6-1.9/5. ABC earned a 3.4/5-1.5/4 with No Ordinary Family, a 3.6/6-1.8/5 with V and a 3.7/6-1.3/4 with Detroit 1-8-7. On the CW, One Tree Hill earned a 1.4/2-0.7/2 and Hellcats was a 1.2/2-0.7/2.

So as you can see, not all shows are “earning” the same amount of viewers. Make sure you know the ratings of the shows you are buying and how much you are paying to reach the people you want to target. Viewing habits change every day and every week. Buying media is not for the weak of heart. Know the “numbers” and then buy accordingly.