What does 10 percent day over day growth actually look like and how did it start?

We started with 200 people, close friends and family. Next day it was 205. Then 210. Very slow and linear at first. Then when we hit a couple thousand users, some people started sharing use cases organically online. Growth started accelerating from one or two percent per day up to six, seven, eight, nine percent. Now we are at ten or eleven percent day over day with zero marketing spend and no creative marketing events driving it daily. Every single day about ten percent of the audience is making a deliberate decision to give up one of their five valuable invites to someone else. That is an extraordinary word of mouth signal. Invites started selling on eBay for around 300 dollars. People were emailing me ashamed, asking if they made the cut into someone else's five friends. There is something very significant in that dynamic.