Monitors are used by almost all professional producers and audio engineers. The claimed advantage of studio monitors is that the production translates better to other sound systems. In the 1970s, the JBL 4311's domestic equivalent, the L-100, was used in a large number of homes, while the Yamaha NS-10 served both domestically and professionally during the 1980s. Despite not being a "commercial product" at the outset, the BBC licensed production of the LS3/5A monitor, which it used internally. It was commercially successful in its twenty-something-year life, from 1975 until approximately 1998. The diminutive BBC speaker has amassed an "enthusiastic, focused, and ... loyal following", according to Paul Seydor in "The Absolute Sound". Estimates of their sales differ, but are generally in the 100,000 pairs ballpark.