Unpopular opinion: our best sales week came from cutting ad spend 60%

Two weeks ago our Google Ads account was bleeding $2,400 a month with a 1.1% conversion rate on a local service campaign, and I got tired of watching money go out the door. I paused the whole thing on a Monday and put the $600 we saved into emailing our past customers a simple 15% off deal, nothing fancy, just a plain text email from our owner's address. By Friday we booked 27 jobs off that email, more than double what ads did all month, and the cost per booking was about $22 versus $140. My boss thinks I got lucky with the timing, but I think we were paying Google to reach people we already owned. Has anyone else tested going quiet on paid search and leaning on your own list instead?