Continuing with Characteristics of Successful SaaS Products, a friend pointed out that while workflow apps are the most common type of successful SaaS app, there’s another category of successful SaaS app: persistent background services. Persistent background services are a class of SaaS apps that once configured run automatically with little to no on-going human interaction, often via API calls.
Here are some example persistent background services:
- Calendly – Scheduling service overlaid on Google Calendar, Office 365, and iCloud to make it easy to schedule meetings with professionals.
- SendGrid – Email delivery as a service for bulk and transactional email messages (e.g. API to send lost password emails, customer email receipts, etc.).
- Twilio – Telephony in the cloud to trigger phone calls, text messages, video chat, and more via API (e.g. click to call from a CRM, text messages for two factor authentication, etc.).
Add persistent background services as another class of successful SaaS app to go along with the workflow apps (the characteristics of successful SaaS apps are still applicable).
What else? What are some more thoughts on persistent background services as another type of successful SaaS apps?
David Cummings on Startups 
Do analytics products classify as persistent background services?