Question: How did Billboard's ranking methodology change after the success of Gangam Style?
About the article "Gangnam Style", section "Music industry".

Candidate passages:
Ngangam (Gangam) is a language of the Gurma people spoken in Togo and Benin. 
Record executives in the music industry believe that music charts will increasingly be filled with YouTube-driven globalised acts from foreign countries.
Sean Carey, a research fellow in the School of Social Sciences at the University of Roehampton, wrote that the flow of popular music will no longer be a single traffic route from North America and Europe to other parts of the globe, but will also move the other way as well.
According to Adam Sherwin from "The Independent", the global web demand for Gangnam Style had short-circuited the "traditional reluctance" of radio stations to play foreign-language songs.
The song is also underlining a shift in how money is being made in the music business.
Although Psy earned more than US$60,000 from music sales of "Gangnam Style" in South Korea alone, he and his music label YG Entertainment have raked in almost US$1 million from advertisements which appear on YouTube videos identified for using "Gangnam Style" in its content.
The "Harvard Business Review" published an article written by Kevin Evers, who explained how "Gangnam Style" had changed Billboard's ranking methodology of its music charts.
Instead of relying solely on radio plays and paid purchases, Billboard started to place a heavier emphasis on digital sales and YouTube views.
As a result of the change, Gangnam Style moved up to the top position of Billboard's Hot Rap Songs music chart.
According to the British Phonographic Industry's report based on Official Charts Company sales data, thanks to Psy's song and Carly Rae Jepsen’s "Call Me Maybe," pop became the UK’s favourite musical genre of the year, taking the lion’s share of the singles market (38.5%) in 2012.
Starting in 2005, "Billboard" changed its methodology to include paid digital downloads from digital music retailers such as Rhapsody, AmazonMP3, iTunes.
This change also allowed songs to chart with or without the help of radio airplay.
This meant that a song did not need radio airplay to be eligible to chart on the Billboard Hot 100.
With this policy change, a song could chart based on digital downloads alone.
On July 31, 2007 "Billboard" changed its methodology for the Hot 100 chart to include digital streams.
The digital information at the time was obtained from Yahoo and AOL's streaming platforms.
This change was made exclusively to the Billboard Hot 100 Chart.
The effect of this chart change was minuscule at the time because it was estimated to account for 5% of the chart's total points.
In October 2012, "Billboard" dramatically changed the methodology for their country, rock, Latin, and rap charts, when they incorporated sales of digital downloads and streaming plays into what had been airplay-only charts.
Another change was that rather than measuring airplay only from radio stations of the particular genre, the new methodology measures airplay from all radio formats.
This methodology was extended to their Christian and gospel charts in late 2013.
On February 20, 2013, "Billboard" announced another change in the methodology for their charts that incorporated YouTube video streaming data into the determination of ranking positions on its streaming charts.
The incorporation of YouTube streaming data enhanced a formula that includes on-demand audio streaming and online radio streaming.
The YouTube video streams that used in this methodology are official video streams, Vevo on YouTube streams, and user-generated clips that utilize authorized audio.
"Billboard" argued that this change was made to further reflect the divergent platforms of music consumption in today's world. 
American college and university ranking systems have drawn criticism from within and outside higher education in Canada and the United States.
Institutions that have objected include Reed College, Alma College, Mount Holyoke College, St. John's College, Earlham College, MIT, Stanford University, University of Western Ontario, and Queen's University.
Critics charged that "U.S. News" intentionally changed its methodology every year so that the rankings change and they can sell more magazines.
A "San Francisco Chronicle" article argues that "almost all of "US News" factors are redundant and can be boiled down to one characteristic: the size of the college or university's endowment.
"Some higher education experts, like Kevin Carey of Education Sector, have argued that "U.S. News and World Report"'s college rankings system is merely a list of criteria that mirrors the superficial characteristics of elite colleges and universities.
According to Carey, ""U.S. News" ranking system is deeply flawed.
Instead of focusing on the fundamental issues of how well colleges and universities educate their students and how well they prepare them to be successful after college, the magazine's rankings are almost entirely a function of three factors: fame, wealth, and exclusivity."
He suggested more important characteristics are how well students are learning and how likely students are to earn a degree. 
The following example provides a good illustration of how the SLIM methodology is used in practice in the field of HRA.