Google Ads is Google's digital advertising platform that allows businesses of any size to show ads in search results, partner websites, YouTube, Gmail and mobile apps. It operates on a pay-per-click (PPC) model: you only pay when someone clicks on your ad.
Since its launch in 2000 (then under the name Google AdWords), the platform has become the most widely used digital advertising channel in the world. According to recent data, Google processes more than 8.5 billion searches daily, making Google Ads a massive gateway to users with purchase intent.
But there is an important nuance that many advertisers overlook: getting clicks is only half the job. The other half, and often the more profitable one, is making sure those clicks convert when they reach your website.
Google Ads does not work like a traditional auction where the highest bidder wins. It uses a real-time auction system that combines two main factors:
The result is the Ad Rank (ad position), calculated by multiplying the bid by the Quality Score. This means an ad with a lower bid but higher quality can outperform a competitor paying more.
The platform is organised into three hierarchical levels:
| Campaign type | Where ads appear | Format | Best for |
|---|---|---|---|
| Search | Google search results | Text | Capturing users with active purchase intent |
| Display | Google's partner website network | Banners, images | Branding, remarketing, broad audiences |
| Shopping | Search results, Shopping tab | Product cards with image and price | E-commerce, product catalogues |
| Video | YouTube and partner video sites | Video (in-stream, bumper, discovery) | Brand awareness, storytelling |
| Performance Max | All Google channels simultaneously | Multi-format (text, image, video) | Maximising conversions with AI automation |
| Demand Gen | YouTube, Discover, Gmail | Attractive visuals, carousels | Generating demand from cold audiences |
Search campaigns are the most direct format. The user types a query into Google, and your ad appears if you have bid on that keyword. The great advantage is intent: someone searching "buy running shoes" is much closer to converting than someone seeing a banner while reading the news.
Performance Max is the most recent format and relies on complete automation. You provide the creative assets (text, images, videos) and Google decides where, when and to whom to show the ads to maximise conversions. It is powerful, but requires a minimum volume of data to work correctly.
Understanding the metrics is fundamental to evaluating the performance of any campaign. These are the ones you need to master:
The percentage of people who see your ad and click on it. It is calculated by dividing clicks by impressions and multiplying by 100. A high CTR indicates that your ad is relevant to the audience.
Benchmark: the average CTR in Search is between 3% and 5%, although it varies significantly by industry.
What you pay on average each time someone clicks on your ad. The actual CPC is usually lower than your maximum bid, as Google only charges what is needed to beat the next competitor in the auction.
The quality rating Google assigns to each keyword-ad combination. It depends on three factors:
This last point is especially relevant: a slow, confusing or irrelevant landing page tanks your Quality Score and makes every click more expensive.
The return on advertising investment. It is calculated by dividing revenue generated by ad spend. A ROAS of 5 means that for every euro invested, you get 5 back in revenue.
If you want to dive deeper into this metric, check our complete guide on ROAS.
The percentage of clicks that turn into the desired action (purchase, sign-up, quote request). And this is where many Google Ads campaigns fail: not for lack of clicks, but because of landing pages that do not convert.
There is an uncomfortable truth in Google Ads: you can have the best-configured campaign in the world and still lose money if your landing page does not convert.
Google Ads brings you the traffic. But what happens after the click depends on the experience you offer on your destination page. And this is where conversion rate optimisation (CRO) comes in.
For a detailed guide on how to optimise your destination pages, we recommend our article on what a landing page is and how to optimise it.
Negative keywords prevent your ad from appearing in irrelevant searches. Without them, you will be paying for clicks from users who will never convert. Regularly review the "search terms" report and add exclusions.
The homepage is not a landing page. If someone searches for "accounting software for freelancers", they should land on a specific page about that product, not your generic homepage.
Without properly configured conversion tracking (Google Tag Manager, offline conversions, attribution), you are making decisions blindly. Set up conversion events for every relevant action.
A low Quality Score makes your clicks more expensive and reduces your visibility. Work on the relevance of your ads and, above all, the landing page experience.
Many advertisers obsessively optimise their campaigns (bids, targeting, extensions) but never test variations of their landing pages. An A/B test on the headline or CTA can multiply conversions without spending a single extra euro on advertising.
Google has progressively integrated AI into its platform. These are the most relevant features:
Google Ads AI is powerful for campaign management, but it has a blind spot: it does not optimise what happens after the click. That remains the advertiser's responsibility, and it is where conversion optimisation makes the difference.
There is no magic number. The budget depends on your industry, competition, the average CPC of your keywords and your business objectives. However, there are guiding principles:
Google Ads is a powerful tool for attracting qualified traffic to your business. But paid advertising is only profitable when the clicks you buy turn into real customers.
It is common to obsess over CTR, CPC and bids, and forget that the real battle takes place on the landing page. Every euro invested in optimising the post-click experience has a multiplier effect on the performance of your entire ad investment.
At Boost we do not manage PPC campaigns, but we are experts in what happens after the click. As a consultancy specialising in conversion optimisation, we help companies transform Google Ads traffic (and traffic from any other channel) into measurable business results.
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