I'm also interested in this. From reading Zero to One and watching the industry it seems that for a unicorn, the app needs to enter the market quickly grow and

I'm also interested in this. From reading Zero to One and watching the industry it seems that for a unicorn, the app needs to enter the market quickly grow and essentially gain a monopoly over the market prior to competitors. This makes it difficult for a competitor to gain market share. For smaller sass apps, the standard business metrics apply: Customers, Customer Churn, Customer growth, Costs. Protection of IP is important but rarely the differentiating factor in this market, take a look at all the email marketing apps for instance. There is no IP there and nothing particularly new, they just provide excellent service at reasonable cost and are still valuable businesses.