Pros
Nielsen is a great way to gain entry into Consumer Products and/or Retail management. Virtually any manufacturer of anything scannable at a supermarket, or any retailer of scannable food utilizes Nielsen data to analyze and understand their business and their consumers. The company has a variety of assets that each have a unique way at looking at the consumer and for the first time, the company seems to be pulling all of those assets together in a cohesive fashion, as in the past, the complexity of the available data made it all but impossible for a novice to extract the insights they need.
Cons
Retaining talent. Nielsen is a huge player in its field (IRI- the main competitor- is floundering), but it simply lacks the resources necessary to truly retain top talent. Most join the company for a few years, for moderate pay and middling benefits, then "cash in" at a major retailer or Consumer Products company. There are a significant number of "lifers", who have resisted the pull of CPG or retail, and they're well compensated. They're a good company; it's just tough to compete with multi-billion dollar conglomerates.