What SEO, PPC and SEM mean
SEO (search engine optimization) is improving your website so it ranks in the organic results, the listings Google orders on its own judgement. Nobody can pay for those positions. Our guide what is SEO explains it in full.
PPC (pay-per-click) is advertising where you pay when someone clicks your ad. In search, that almost always means Google Ads, with Microsoft Advertising as a smaller alternative. The ads appear in positions marked as sponsored.
SEM (search engine marketing) is used in two ways. Some use it as an umbrella for all search marketing, SEO and paid together. Others, including many ad platforms, use it to mean paid search only. When someone offers "SEO and SEM marketing", ask which they mean.
SEO vs PPC at a glance
The two channels answer the same searches but behave very differently.
| SEO | PPC (Google Ads) | |
|---|---|---|
| Where you appear | Organic results and, for local searches, the map results | Sponsored positions above, below or beside the results |
| Cost model | Investment in website, content and authority; no cost per click | You pay per click, plus management; costs stop when you stop |
| Speed | Typically months before clear results | Visible as soon as campaigns are approved and running |
| Durability | Results can last and compound after the work | Visibility ends when the budget ends |
| Control | Indirect: Google decides rankings | Direct: you choose keywords, budget, locations, schedule |
| Testing | Slow to test messages or offers | Fast to test keywords, headlines and landing pages |
| Trust | Many users see organic listings as more credible | Clearly labelled as advertising |
Advantages and disadvantages of SEO
Advantages
- No cost per click: a page that ranks keeps attracting visitors without paying for each one.
- Work compounds. Good content and earned authority strengthen the whole site.
- Covers the full buyer journey, from early research questions to "near me" searches.
- Builds the foundation that AI search tools also draw on.
Disadvantages
- Slow to start; typically months, longer in competitive markets.
- No guarantees: Google decides, and algorithm updates can shift positions.
- Requires sustained investment in content, technical quality and authority.
Advantages and disadvantages of PPC
Advantages
- Immediate visibility, useful for launches, seasonal demand and new services.
- Precise control over keywords, locations (down to specific cities or provinces), schedule and budget.
- Fast, measurable testing of offers and landing pages.
- Can reach searches where your organic position is still weak.
Disadvantages
- You pay for every click, and costs in competitive categories can be high.
- Visibility stops as soon as you stop paying.
- Poorly managed accounts waste money quickly on irrelevant searches.
- Some sectors have extra advertising restrictions; healthcare, financial services and legal services, for example, are subject to specific Google Ads policies and professional rules.
What drives that spend is covered in our guide to Google Ads cost.
SEO or PPC: which should you choose?
The right choice depends on your situation more than on the channel itself.
- Choose PPC first when you need enquiries soon, launch a new service or location, sell something seasonal or time-limited, or want to test which searches convert before investing in content.
- Choose SEO first when you plan for the long term, operate in a market where people research carefully before buying, want to reduce dependence on ad spend, or already get some organic traffic you can build on.
- Use both when the stakes justify it: ads for immediate coverage, SEO for lasting visibility and lower cost per enquiry over time.
For clinics and practices, a common pattern is ads for high-intent searches such as specific treatments in the local area, while SEO builds the service pages, trust signals and Google Business Profile that support both. Our page on websites and marketing for medical clinics describes how that looks in practice.
Why SEO and PPC often work best together
- Shared data. Paid search shows which searches lead to enquiries; that tells you which pages to build for SEO.
- Coverage. Where you rank organically, you can reduce ad spend; where you do not yet, ads fill the gap.
- Better landing pages. Pages built for SEO tend to be clearer and more complete, which often helps ad performance too.
- More presence. Appearing in both the ads and the organic results for an important search reinforces your brand.
One misconception to clear up: Google Ads does not directly improve your organic rankings. Google keeps the two systems separate. The benefit is indirect, through insight and coverage.
Where AI search fits in
A newer question is "AI vs SEO": should you optimize for ChatGPT, Perplexity and Google's AI Overviews instead of classic search? In practice it is not an either-or. Google says the usual SEO best practices apply to its AI features, and AI assistants depend on web content they can access and trust. AI search optimization builds on SEO and adds work specific to those engines. We explain the differences in what AI search optimization is.
On-page vs off-page SEO
When people compare search channels, the terms on-page and off-page SEO often come up. On-page SEO is everything on your own site: content, titles, headings, internal links, structured data and page experience. Off-page SEO is what happens elsewhere: links and mentions from other sites, reviews and your wider reputation. Both are part of SEO; neither involves paying per click.
How we approach SEO and PPC
We look at search as one system. In some cases we advise starting with paid search to learn quickly; in others SEO is the better first investment and ads would only burn budget. Our SEO services and Google Ads management are planned together, with honest reporting on enquiries rather than clicks alone.