"Cascade", released as a single in 1993, introduced the commercial music world to the new FSOL sound. Despite its length, clocking in at nearly forty minutes and stretched over six parts, the track made the UK top 30, and previewed what was to come. In 1994, they released Lifeforms to critical acclaim. The album featured unconventional use of percussion interspersed with ambient segments. The eponymous single from the album featured Elizabeth Fraser of the Cocteau Twins on vocals. The album itself featured epic, ambient soundscapes, with tracks flowing from one to the next with no pauses in between. Throughout the record, familiar motifs and samples repeated themselves, sitting alongside tropical birdsong, rainfall, wind and an array of other exotic sounds, lending the album a natural, organic feel, backed up by the environmental landscapes that filled the artwork booklet. Brian Dougan's father was involved with the BBC Radiophonic Workshop which was a heavy influence in the almost musique concrete feel to Lifeforms. The album was also a top 10 hit on the UK album chart. Cobain has said that around this time that journalists would come to talk to them and one of the first things they would ask would be if they liked Brian Eno (whom they cite as an influence), to which they would laugh and say that they were about looking forward, not to the past. It was, to them, very much a new work rather than just another Eno-type ambient album.  We wanted to release a very immersive, mind-blowing piece of music that was long and would deeply drench you in it...Lifeforms was redefining 'classical ambient electronic experimental' - that was the phrase we used.  That year, they released the limited edition album ISDN, which featured live broadcasts they had made over ISDN lines to various radio stations worldwide to promote Lifeforms, including The Kitchen, an avant-garde performance space in New York and several appearances on the late John Peel's celebrated BBC radio Sessions shows. These shows marked the evolution of the Kiss FM shows of 1992 and 1993, moving away from DJ sets and into ambient soundscapes, with previously released material performed alongside unheard tracks. One live performance to BBC Radio 1 featured Robert Fripp performing alongside the band. The released album's tone was darker and more rhythmic than Lifeforms. Cobain stated that with ISDN they had wanted to achieve something epic and grand but no matter how much technological or personal support they had (and they had everything they could have possibly wanted) they never got to truly do what they envisioned; he admits to wanting too much at this time, even though the album was successful; the 90s, for Cobain in particular, were a time of frustration and feelings of not being able to do what they wanted to, because the technology at the time didn't fit the band's ideas. The following year, the album was re-released with expanded artwork and a slightly altered track list as an unlimited pressing.

Answer this question "How many records did it sell?" by extracting the answer from the text above.
even though the album was successful; the 90s, for Cobain in particular, were a time of frustration and feelings of not being able to do what they wanted to,