Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of online family history resource (Nasdaq: ACOM) plunged 17% on Monday after NBC said it will not renew its sponsored show Who Do You Think You Are? for a fourth season.

So what: The show -- in which celebrities trace their family history using Ancestry's services -- has been a major promotional vehicle for the company in recent years, so the cancellation is naturally triggering concerns over slowing growth going forward. Of course, Ancestry's current rate of subscription revenue growth isn't all that much higher than when the show started, making today's sell-off seem like a bit of an overreaction.  

Now what: While NBC's decision deals a short-term blow, I'd expect Ancestry to find other creative ways to market its services over the long haul. "We have a great partnership with the show's producers, Is or Isn't Entertainment and Shed Media, and we look forward to exploring other avenues of distribution," CEO Tim Sullivan reassured investors. More important, with the stock flirting with a new 52-week low and trading at a forward P/E of 11, betting on management doesn't exactly come at a high price.

Interested in more info on Ancestry? Add it to your watchlist.

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