Arguably, the first video to be called a viral sensation was the Evolution of Dance, which as of today, has received 158,913,650 views. It currently sits at number 8 on Youtube's most viewed videos list. It was a huge success when it came out four years ago and everyone was talking about it. Contrast Evolution of Dance 2, which has received less then 10% of the original views and think about how many times you've talked about Judson Laipply since the original video came out. Yes, Judson Laipply. That's the name of the person in the Evolution of Dance video. Bet you didn't know that.
Currently the number one video of all times on youtube with 410,894,455 views, is Baby by Justin Bieber featuring Ludacris. This video has racked up an incredible number of views in just 10 months, which is pretty impressive. Justin Bieber may be one of the few who move from one hit wonder to success via youtube.
Another thing to note in the top 10 list of youtube videos is that only 2 of them are UGC. Charlie bit my finger - again! sits at #3 with 259,233,077 views and Hahaha sits at #10 with 150,711,439 views. These 2 are almost certainly one hot wonders since it was the circumstances that made them hits. not the content alone. The other 8 are all professionally made pieces of content.
I sometimes wonder if we in the advertising business are really in-tune with what consumers are really thinking. If you look at One Club / Best of the Digital Decade > Top 10, you'll see that Subservient Chicken is at the top of the list. (To be honest, I've always been miffed about this because I used a similar technology about four years earlier, but hey, their content was more fun.) But, when I talk to students and people outside of the ad industry, none of them have ever heard of Subservient Chicken. And while it did a great deal for Crispin, I'm not sure what it did for Burger King.
So decide what you want to be. Sure, there's value in being a one hit wonder and it's easier, but I think there's more value in being something better then that. But you shouldn't confuse being a one hit wonder with being a long term success. That takes a lot more work.