Pros
Depending on the area, most people work from home. This can be a con if you are new to the company and want to build relationships with co-workers. Great place to START your career and gain valuable experience and knowledge. Take this experience and go somewhere that will value you.
Cons
I have seen many changes over my three decades working for Nielsen. The last ten years have been a revolving door with layoffs every 6 mos. Nielsen does not value it's employees only the bottom line. They use to care what employee thought. The company used to have annual reviews of themselves where every employee is encouraged to participate in review the company and department they contribute to. This allowed the company to look at areas for improvement. This is no longer a priority. They are trying to be a technology company and failing miserably as they don't have a clue. Do not build something expecting clients to buy into it, There is no integrity as they will promise the client things they know they cannot deliver.