I'm a day late here, but I made a viral song way back in 2000 when I was in my 20s. That was long before 'viral' was a phrase anyone used; the attention I got was mostly offline. I uploaded the song to mp3.com which was, along with napster, the main method of distributing music online. A few days later they made a press release about it and the phone calls began.
The first came at work from a news service that did a short interview. After that I would start to get calls at 5am when the east coast morning shows were getting going, asking for an interview or for me to perform the song live on air. I hung up on the first one that called thinking it was rude to be called so early, but as soon as I hung up the phone rang again. I gave in and did a groggy interview. As soon as it was over, the phone rang again. My roommates pretty much hated me. And that's how it was for the next four weeks: every morning the phone would ring at some ungodly hour and I'd do interviews until I left for work.
I'd answer emails at work during breaks, or take a few calls at lunch for radio stations big enough for me to recognize. Drew and Mike in Detroit called me a few times just to make fun of how big of a nerd I was.
The song was shown on some TV shows as well, most notably Entertainment Tonight. I had a bunch of friends over for that, as they played a clip from the song right on the show. A friend went online to look for my song on napster, and then chat with people that were sharing it to brag that he was at my house. A few people though it was awesome, most didn't care, and some took the opportunity to make fun of me.
All-in-all the experience was pretty bittersweet. I sold some shirts and got some royalties from mp3.com (imagine getting money for a song online—those were the days). Just a few thousand bucks, but I was thrilled at that. Being nagged at all hours of the day, being made fun of by strangers, those parts sucked. Then came the worst part: I replied to a fan that had emailed me and she said I was "so four weeks ago". I had become irrelevant. After finally adjusting to the endless attention, it was gone. The Internet had already spit me out.
I kept making music but didn't release anything fast enough to capitalize on the popularity, which has turned out to be one of my life's regrets. Knowing that millions of people have heard one of my songs is an awesome thought, and the best part of the experience. Beyond that, I learned a lot about fame: even the small sliver I had for just a small amount of time was terrifying. And that was before the internet was properly embedded in our society; I think things are orders of magnitude more hectic for people whose work goes viral now. I envy the scale of their success but also feel bad for the level fame.