Surely the key point is how many of these viewers are female? If they are mostly males, & probably existing racing fans, then it isn't such a great statistic. And I suspect this may be the case - there's all us lot for a start!
Regardless of gender it is a great statistic, as I wrote earlier in this thread. My wife know of my Motor Sport obsession, but have zero interest herself.. I told her about the first race in the W series, which then brought up and talked about at dinner with friends 2 days later... it was the first time ever she initiated a Motor Sport discussion, and she did it to tell the other girls how happy she was the series existed.
Even if all 400.000 viewers were male, at lest some of them will like me share with their significant others, the knowledge of W series will spread to some who never had any interest, I am 100% convinced some of them will be watching at least one race, I know for sure that my wife will watch at least some of the first race shown on NBC.
Again.... no doom, no gloom... glass is half full and filling.