Content revised 20 October 2026.
SEO improves organic search visibility. SEM often means paid search advertising. Here is how to compare the work, costs and results without mixing them up.
Start with the result you're looking at
An organic search listing and a search ad can appear on the same results page, but they reach that page through different systems. SEO works on your website and its organic visibility. A paid search campaign competes for advertising placements. The term SEM is sometimes used more broadly, so ask what a proposal includes before comparing prices.
What the work looks like
For an online furniture store, SEO might involve clearer category pages, useful product details and fixing duplicate URLs. A paid campaign might promote a particular collection to people making relevant searches. Both need a usable landing page. Neither solves a confusing delivery policy or a broken checkout on its own.
Compare the costs honestly
- SEO can involve research, writing, development and ongoing review. Organic visits are not a reason to call the work free.
- Paid search usually separates advertising spend from management and creative costs.
- Both need measurement and someone responsible for acting on the results.
Read the reports separately
Keep paid clicks and organic clicks identifiable in your reports. Compare relevant enquiries or purchases alongside visits. Buying ads doesn't purchase better organic rankings, and stopping ads doesn't prove that an organic position has changed. The useful question is which mix of work supports your business at a cost you can manage.
Official guidance: Google SEO fundamentals.