Stopped chasing every lead and revenue went up 22% in one quarter

For like 2 years I treated every inquiry like gold. Someone emails saying they might need services in 6 months, I'd spend an hour on a custom proposal. Took a call from a guy who wanted me to redesign something he hadnt even started yet. Then last January I had a month where I worked 70 hours, closed nothing, and one of my real clients sent a note saying they felt ignored. That hit me. So I started qualifying hard before any real work. Ask about budget, timeline, and what they tried before. If they hesitate on any of those, I send a quick generic quote and move on. Now I put that time into the 3 or 4 clients that actually pay. Has anyone else tried cutting off the tire kickers and seen their actual profit jump? Or does it feel too risky when things are slow?