There are famous Internet animals, and then there is Grumpy Cat. The one-year-old feline, whose perpetually frowning face turned her into a massive online sensation over the past year, officially became a one-cat empire when she graced the cover of New York magazine’s “Boom Brands” issue in October. The world learned that the estimated value of the Grumpy Cat brand — which includes a coffee line, a New York Times-bestselling book and even a movie deal — is worth an estimated $1 million. The lesson from all this, according to New York magazine? Invest in cats.