Nielsen Co., the which measures viewership for TV shows, will start assessing audiences for online streaming services such as Netflix Inc. and Amazon.com Inc.'s Prime this year, according to a Bloomberg report. “That will be the last significant portion of overall television content viewing that we don’t already measure,” Nielsen CEO Mitch Barns told Bloomberg on Tuesday. “We really will have a full set of capabilities in the market to measure what we call the total audience across all screens, devices and platforms.” The article said Netflix and Amazon.com...