I dunno. I try not to get too involved with the whole celebrity craziness... mostly, I try to keep in mind that they're just regular people with unusual jobs. So when a celebrity that I admire dies, It makes me a little nostalgic and I might buy a copy of a movie that they were in or a magazine or something. But when a musician dies, I guess it depends on how much their music soundtracked my life... When I found out that Elvis was dead, I was heartbroken. I remember learning of River Phoenix's overdose and being sad. After Kurt Cobain's suicide, I was angry and upset for weeks. And yet somehow Michael Jackson's death impacted me more than these. I wouldn't say, however, that I liked him more or found him more interesting after his death. I also wouldn't say that he's my favorite musician, cause he's not. I think it's just that he soundtracked such a significant portion of my life. His videos were some of the first that I ever saw on MTV... and I would try and watch them over and over again. And when a new video came out, watch out! Man, it was an event. They had like this whole night where they were teasing you about it. And you knew that if you didn't watch the premiere that you would likely never see the entire video again because of censorship or what have you. This was way before the internet and youtube. lol.
Anyway, I guess what I'm saying is that I don't think that death exactly makes a celebrity more popular... maybe it's just that people are suddenly reminded of how much influence some of them had on us... or we're nostalgic for that time in our lives when we listened to them or watched them or whatever.