http://en.wikipedia.org/wiki/Nirvana_discographyHere are all the albums released. I'm no fan of wikipedia, but it has an organized source of their albums.
Note that everything up until Cobain's death, which is the MTV Unplugged album was released, sold fairly well.
Then, the box set, Singles, sold very little, didn't even chart. Then, the following album, Wishkah, sold fairly well. It went platinum, yes. But if you'll check this next link.
http://en.wikipedia.org/wiki/Foo_Fighters_(album), you will clearly see that it was released around a year after the Wishkah album, and the Foo Fighters album was met with large phenomenon, because it was a project from the drummer of Nirvana, thus causing people to make a big fuss about it, as well as comparing them to Nirvana, having Nirvana be in the attention as well. Also, since it was the first LP, not box set, but LP to be released after Cobain's death, it was guaranteed to sell well. Then, six years later, the band finally released the Nirvana Greatest Hits album. It was met with attention because Foo Fighters were finally a very popular act, and were criticized by critics as possibly gonna rise to be more popular. It was also met with attention because it was had a new song, a new lawsuit between who owns the royalties to the songs, and the Foo Fighters album One By One was released around the same time. The next album, With The Lights Out, was certified platinum, yet it only sold around 100,000+ copies, which shouldn't have made it even eligible to be certified gold. The next album, Sliver: The Best of the Box, was met with only 35,000+ copies sold. Now I don't know about other countries. Those sales might be great there, but these are American sales, and those aren't really high here. Platinum is 1,000,000 copies, Gold is 500,000, and I don't believe we have silver. And you know why the last two had low sales? Because, there was nothing of big importance that gave Nirvana the push for hit albums. Foo Fighters had become more of their own type of band. Courtney Love had become nearly silent to the public.
If you still don't believe me, here is probably the best source.
http://www.riaa.com/gold...rt=Artist&perPage=25Most of the certifications are from their Nevermind-MTV Unplugged sales, which was before Cobain's death. Everything else is the boxsets, which had not too many certifications.
http://www.riaa.com/gold...php?table=SEARCH_RESULTSAnd just to prove that "Smells Like Teen Spirit" was their only profitable song.
Also, if you can't access some links, check out riaa.com and look up nirvana.