A lot of people feel that buying singles is a waste of money. I've been an avid collector of singles since I was a child in the *gasp* early '70s, and strongly disagree.
When Nevermind came out, I was broke. VERY broke. I'd just moved halfway across the United States, and got robbed along the way, so I arrived in Arizona with little more than the ID in my wallet. It was November 1991, and radio and MTV had just started playing 'Smells Like Teen Spirit' by this unknown Seattle 'grunge' band called Nirvana. I liked it. A lot Fortunatly the kind (or would that be greedy) folks at Geffen released the song on a cassette single, which was very cheap. Since Nirvana was considered an unknown new artist, the cassette single was even cheaper, so I bought it the first time I saw it without hesitation. I was particularly blown away by how good the b-side 'Even In His Youth' was. To this day it's still one of my favorite Nirvana songs, and it amazes me how many younger people who say they just LOVE Nirvana have never heard it. One of the many things I've learned by collecting singles was that I could get a quick idea of how much I'd actually like a band's album by how much I liked the b-side they stuck on thier hit single. 'Even In His Youth' is an amazingly intense song, with all the angst and aggression that went on to make Nirvana legendary, and while it doesn't have as much studio polish, is much better than many of thier album tracks. This single was my main motivation to buy "Nevermind" and "Bleach" right at the beginning of 1992. If you've never bought a single before, and you consider yourself a Nirvana fan, this is the perfect single to start with.
The bottom line is if you're a Nirvana fan, you need this, because your collection is truly lacking without it. Also, if you don't collect singles already, you should really try doing it for a while, you might be shocked at how many b-sides rock your world.