Going viral is simple. You send X people to your site, and they on average send at least X+1. For example, you link to your site on HN, and receive 100 visitor

Going viral is simple. You send X people to your site, and they on average send at least X+1. For example, you link to your site on HN, and receive 100 visitors day one. It's a great service, and those 100 people share it with enough people to receive another 150 visitors the next day. Your new visitor traffic per day goes... 1. 100 2. 150 3. 225 4. 338 5. 506 6. 759 7. 1,139 8. 1,708 9. 2,563 10. 3,844 ... 20. 221,683 Within a few weeks you're receiving a quarter million new visitors a day. Now, if HN sends 100 visitors day one, and those users generate 80 new visitors day two, you get... 1. 100 2. 80 3. 64 4. 51 5. 41 6. 33 ... 20. 1 Now you end up with only one visitor after three weeks. In one case you're at the top of the world with the next big hit, and the other you have absolutely no traffic. You see situation number two happen all the time. You get a spike of traffic and it fades away over the following week. As you can see above though, the difference in a spike of traffic fading away, or going through the roof isn't that large. We're not talking about one site being awful and the other being the best thing since sliced bread. We're talking about 100 people referring 80 people and 100 people referring 150 people. Not a huge difference in interest, but the traffic results can be staggering.