Now we have a monopoly. Billboard Information Groups, SoundScan, Radio And Records, and Nielsen all controlled by V.N.U. With every merger it gets a little more accurate. Good deal for everyone involved in the industry.
My understanding is that Radio And Records has always been strong in the research department. They also host the most popular and respected seminars on marketing and industry analysis. Their charting methods have always been questionable, so Billboard will take up the slack in that department.