Nielsen has upgraded its July decision to do a strategic view of its Buy Segment to one which puts all options on the table – including a sales of all or any part of the business. It has asked JP Morgan and Guggenheim Securities to offer a view, which means doing some valuations work on how much they might get for all or part of the business. It says that Total Audience and the Connected System are all steam ahead, while data on what people buy is doing less well, as are emerging markets data and GDPR regulation is creating problems for the business. Rival Kantar Media, owned by WPP, night provide an answer – it has a buy side…