The K-factor measures virality: multiply invitations sent by the conversion rate of those invitations. If you send 5 invites with a 30% conversion rate, your K-factor is 1.5. Anything above 1 means exponential growth.
Do you want to know the formula for going viral? Virality can be figured out using what's called the K-factor calculation. K equals I times C, where I stands for invitations and C stands for conversion. If the K-factor is more than 1, you have a viral product. For example, I'm able to invite 5 people and get 30% to convert. My K-factor is 1.5 and will continue to grow so long as those rates stay the same.
