Search intent versus interruption
Google ads show up when someone is already searching for a service, like “emergency plumber”. The person wants help now. Facebook and Instagram ads show up while people scroll. They did not ask for you, so the ad has to earn attention.
When Google tends to fit better
Urgent or high-intent jobs, such as repairs, emergencies and replacements, usually suit search ads, because the customer is looking right now.
When Facebook tends to fit better
Considered projects people plan for, such as remodels, decks, patios and landscaping, can work well on social, especially with strong before-and-after photos and an offer.
Either way, the foundation matters
Both send people to your site and your profile. If those are slow, empty or have no reviews, you pay for clicks that do not turn into jobs. Get the foundation right first, then test one channel at a time.