There is no new dynamic in play, this has been happening to just about every one hit wonder since recording was invented. Some stay, most go.
The idea here is that follow-through has to be made by everybody, artist, label and so on to take an opportunity like this and to turn it into a marketable brand.
I'm reminded of:
http://www.youtube.com/watch?v=IOu0DuxFAT0
Which I'd never heard of before running into it on digg, it's musically mediocre, has a fantastic video but ultimately failed to convince me to go out and buy an album.
The internet can't be given credit for the success and it can't be given the blame for subsequent failure, it is just a tool and how you use that tool is up to you.
Caring about an artist means to go and visit their concerts, becoming a successful artist means that you're going to have to slog through the 'building a loyal fan base' trough of sorrow somehow and as far as I know outside of throwing huge marketing budgets after fan acquisition (talent optional) there are no short-cuts there.
By the way, a similar issue faces websites, you may be able to get that front page on HN with your new offering but that won't make much difference in the long run, you'll still have to have the staying power and the determination to see it through for a long period without being sure if it is going to work out or not. And if you do the chances of it working out go up.
Overnight success is not a right, and if you've been handed a free head-start you can't blame your tools if it subsequently does not pan out the way you intended.