Try not to use cardinal scales when ordinal and even rational measures are available. Saying something is "8th biggest" imparts relatively little information and can even lead to unjustifiable conclusions. The 8th biggest may be only one larger than 9th but one thousand smaller that 7th. Use the actual size of the market rather than where it ranks.
The TV market size debate has gone on ad nauseum on the other B1G thread, particularly after the last raid. I'm not trying to get published here but for the sake of discussion here are your numbers.
Rank Designated Market Area (DMA) TV Homes. % of US
1 New York 7,433,820 6.495
2 Los Angeles 5,654,260 4.940
3 Chicago 3,492,850 3.052
4 Philadelphia 2,950,220 2.578
5 Dallas-Ft. Worth 2,489,970 2.175
6 San Francisco-Oak-San Jose 2,476,450 2.164
7 Boston (Manchester) 2,409,080 2.105
8 Atlanta 2,369,780 2.070
9 Washington, DC (Hagrstwn) 2,321,610 2.028
10 Houston 2,106,210 1.840
11 Detroit 1,926,970 1.684
12 Phoenix (Prescott) 1,855,930 1.622
13 Tampa-St. Pete (Sarasota) 1,822,160 1.592
14 Seattle-Tacoma 1,819,970 1.590
15 Minneapolis-St. Paul 1,730,530 1.512
I'd say that the 8th largest market is still very significant