I do pay attention to it each week. It just intrigues me how much a song/album sells, what song is popular and people are buying the most, what records on the charts are being broken, etc. If a song/album I like doesn't do well on the charts, or let alone doesn't chart, it's not like I'll refuse to listen to that album/song just because it didn't chart anywhere. I feel some people assume that if you like the charts/sales, you'll ONLY listen to artists that chart on there, which is definitely not the case here.
kinda, depends on the artist, if he/she hasn't had any hits for years and he/she released new song that have potential, i'd pay attention to it. example: Gwen with Used To Love You