During the 1990s, CD single releases became less common in certain countries and were often released in smaller editions, as the major record labels feared they were cannibalizing the sales of higher-profit-margin CD albums. Pressure from record labels made singles charts in some countries become song charts, allowing album cuts to chart based only on airplay, without a single ever being released. In the US, the "Billboard" Hot 100 made this change in December 1998, after which very few songs were released in the CD single format in the US, but they remained extremely popular in the UK and other countries, where charts were still based solely on single sales and not radio airplay. At the end of the 1990s, the CD was the biggest-selling single format in the UK, but in the US, the dominant single format was airplay. With the advent of digital music sales, the CD single has largely been replaced as a distribution format in most countries, and most charts now include digital download counts as well as physical single sales.