This question tests the understanding of digital marketing strategies and the use of standalone media properties. The correct answer is C, as BabyCenter illustrates how companies use standalone media properties to achieve broader marketing objectives beyond just selling their own products. Option A is incorrect because BabyCenter promotes a wide range of products, not just exclusive ones. Option B is incorrect as the focus is not on direct competition but on providing a platform for various products. Option D is incorrect because the creation of BabyCenter does not indicate the decline of traditional marketing strategies but rather an expansion into digital spaces.