Both platforms sell attention, but not the same kind. Before you choose, only one question matters: are people already looking for what you sell? Google Ads answers demand that already exists: your ad appears at the moment someone types their search. Meta Ads (Facebook, Instagram) creates demand: your ad lands in a feed where nobody was expecting you. In both auctions, the highest bid doesn’t necessarily win: ad quality counts too. You judge a campaign by the cost per customer won, never by the cost per click. Two platforms, two different moments Google Ads and Meta Ads are often presented as two competitors you have to choose between. Yet they don’t sell the same thing. On Google, a person has a need and types it: “plumber Casablanca”, “car rental Marrakech airport”, “restaurant POS software”. Your ad arrives at the exact moment the demand is expressed. On Facebook and Instagram, nobody is looking for anything. People scroll through a feed, and your ad slips in between two posts from friends. It doesn’t answer a question: it has to spark desire, or at least curiosity, within a second or two. That calls for different writing, different visuals, and often a different offer. Hence the first question, before any setting: are people already looking for what you sell? If so, Google is the shortest path to them. If your product is new, visual or bought on impulse, Meta is often the only place to get it discovered. How Google chooses the ads it shows Every search triggers an auction. For each competing ad, Google calculates an Ad Rank. According to its official help, it depends on the bid amount, the quality of the ad and of the landing page, the minimum thresholds Google sets, the competition on that search and its context: where the person is, their device, the time, the words used. The direct consequence: an ad that matches the search, and leads to a useful page, can beat a competitor bidding higher. Paying more isn’t the only way to win, and rarely the cheapest. Quality Score: a warning light, not a setting Google Ads shows a Quality Score from 1 to 10 for each keyword, calculated from the expected click-through rate, ad relevance and landing page experience. Google specifies that it is not used in the auction: it’s a diagnostic tool. It helps you spot what’s wrong, not something to optimise for its own sake. How Meta decides who sees your ad On Facebook and Instagram, an auction takes place every time a person could see an ad. Meta compares the total value of each ad, which combines three things: the advertiser’s bid, the estimated action rates (the likelihood that this person will do what you’re trying to get) and ad quality, judged in particular by the reactions of the people who see or hide it. Here too, the best ad can beat the most expensive one. That’s why, on Meta, the creative does most of the work: it’s what stops the scroll, what gets people reacting, and therefore what improves the algorithm’s estimate of your ad. The learning phase After an ad set is launched, or significantly edited, Meta’s delivery goes through a learning phase during which results are less stable. According to Meta’s help, it generally ends after around fifty optimisation events within the seven days following the last significant edit. Tweaking a campaign every two days keeps it stuck in learning. When to choose one, the other, or both Google first when the demand exists and can be put into words: an emergency service, a tradesperson, a clinic, a training course, a product people compare before buying. Meta first when you have to show to convince: a clothing collection, a restaurant, an event, a launch offer, a product nobody thinks to search for. Both together when the buying journey is long: Meta makes the brand known, then Google catches those who search for it by name or by what it sells. Many sales now go through a conversation. A Meta ad can open WhatsApp or Messenger directly instead of a web page: for a business that already sells by chatting with its customers, it’s often the most natural format. What to measure before you spend The trap is the same on both platforms: they display flattering numbers that don’t tell you whether the campaign pays off. A click, a view, a like are not customers. Define the action that really counts: a call, a form sent, a WhatsApp conversation, a purchase. That’s what you ask the algorithm to optimise for. Set up tracking for that action before launching: the Google tag, the Meta pixel and, ideally, Meta’s Conversions API, which sends events from your server and not just from the browser. Record what happens to the leads: how many are called back, how many buy. Without that feedback, you’re optimising forms, not sales. Let it run long enough to judge: three days of data say almost nothing, especially on Meta during the learning phase. That last number, the cost per customer, is what tells you whether the money is well spent. An expensive click that brings a customer is worth more than ten cheap clicks that bring nobody.