Nine times out of ten it's one of six boring causes — and Google publishes the list. The tenth time it's the cause nobody checks: the ads work fine, and what's broken is the page the click lands on. Here's the checklist in the order that finds the problem fastest.
Google's own troubleshooting guide covers the mechanical causes: the campaign or ad is paused or removed, billing failed, the daily budget is depleted by lunchtime, the ad is still under review or got disapproved, bids are below what the auction takes, or the targeting is drawn so tight almost nobody qualifies. Check status columns before theories — “paused since March” has ended more mysteries than any strategy session. Two more Google-documented gotchas: new campaigns and freshly-edited ones sit in a learning phase for days, so constant fiddling resets the clock; and searching for your own ad repeatedly without clicking teaches Google to stop showing it to you — use the Ad Preview tool instead.
Ads that run but produce nothing usually fail on economics, not settings. Broad keywords burn budget on searches that were never buyers (“free,” “jobs,” “DIY” variants) — the search-terms report shows exactly what you paid for; read it and add the negatives. Bidding on clicks you can't afford to win halfway is worse than not bidding: $200 of budget in a $30-per-click market buys six visitors and no data. Tight and boring beats broad and hopeful — your services, your towns, and the searches where someone is ready to hire.
If ads deliver clicks and the phone stays quiet, the ads aren't the problem — the landing experience is. A slow page, a homepage instead of a service page, no visible phone number, no proof (reviews, photos, prices) — the click bounces, and no bid strategy fixes that. Before raising budget, fix what the click lands on; before running ads at all, make sure the free foundation — profile, reviews, a site that answers real questions — converts. Paid traffic pointed at weakness just spends faster. If that foundation check sounds like the harder problem, that's the one we actually solve.
The ad shows for searches it shouldn't, or says nothing worth clicking. Read the search-terms report, add negative keywords, and rewrite the ad to name the service, the place, and a reason to pick you. Generic ads get generic ignoring.
The landing page is losing them: slow load, wrong page, no phone number visible, no proof. Send clicks to a service page with reviews, prices, and a tap-to-call number — the ad's job ends at the click; the page does the converting.
New and heavily-edited campaigns spend days in Google's learning phase, so judge after a few weeks of stable settings — but judge on booked work per dollar, not impressions or clicks. No tracked conversions after meaningful spend is a verdict too.
If nobody's reading the search-terms report monthly, you're paying for waste either way. Whoever runs them — you, us, anyone — hold the ads to one number: what a booked customer costs. An account manager who can't answer that is decoration.