This is a smart way to make retainers tangible: clients renew when they can see what you are monitoring. One addition from my side is to pair the uptime and SSL checks with a short monthly summary that translates each alert into a business risk, not just a status. I'm building RadarLeads, a tool for finding local businesses with weak or missing sites, and the same principle applies: the visible gap is what starts the conversation. How are you handling clients who want the checks but not a full retainer? Disclosure: I'm affiliated with RadarLeads.