John Kim on growing Sendbird
This is another gamer turned RTC SaaS founder (Slack, Discord). What's also interesting is he switched from a B2C "Mom app" (company was called Smile Family), a community app for Moms to building a messaging SDK for businesses. Of course how this happened was John Kim tried integrating a messaging SDK into his Mom app but wasn't able to find one that fit his needs (unclear why Twilio, which at that time was already a 5-6 yr old company didn't do the job) and so he built a messaging server, which then sold more successfully than the Mom app.
The Mom app wasn't accepted into YC in 2013. But Sendbird then was in 2015 (W2016).
First customer: a small gaming studio at $50/mo. Had 20 friends and family customers before getting accepted to YC and going GA in early 2016.
Next few customers: Came from content, SEO and the developer community (YC, HN, Stackoverflow).
Product: a messaging API (today they also have voice and video) that developers can integrate into (eg:) their dating app for 2 people to chat with each other, or into a delivery app for a customer to chat with the delivery person or a rideshare app for a rider to chat with the driver.
Pricing: By MAUs. Eg: 5K MAU = $400/mo. There is no cap on #messages and customers are encouraged to send as many messages as they like.
ACV: Ranges from $5K to $Ms, averaging at about $30K
#customers (Mar 2020): 422 that ran 3000 apps
ARR (Mar 2020): ~$30M. Growing at T2D3 rate. 40% US, 30% EMEA, 30% APAC.