SEM (search engine marketing)

Which definition applies?

Wikipedia describes SEM as promotion of websites in search results primarily through paid advertising that may incorporate SEO, and adds that in some contexts, particularly in commercial advertising and marketing communities, the term is used exclusively for pay per click advertising. Optimizely says the industry now uses SEM almost exclusively for paid search, even though it once included organic strategies. The context decides which one is meant, and a short clarification saves misunderstandings in briefings and reports.

How does paid search fit with organic search?

Paid listings are ads. Organic listings come from the search engine’s automated ranking. Google states that it does not accept payment to rank a site higher, so buying ads does not change organic positions. Both channels start from the same searches. Keywords that convert well in ads can show which topics deserve organic content, and organic data shows which terms already bring visitors.

The typical steps of a paid search campaign are keyword research, setting up campaigns, writing ad copy, optimizing landing pages, managing bids and budget, and ongoing refinement.

Example

An online shop runs ads for “buy running shoes” and optimizes its category page for the same term. The ads bring visitors on the first day. The page optimization may take weeks or months to affect organic rankings.

FAQ

What is the difference between SEM and SEO? SEO improves organic rankings. SEM in the narrow sense means paid ads, and in the broad sense includes SEO.

Which platforms are used for SEM? Google Ads and Microsoft Advertising are the two main platforms named by Optimizely, which still uses the earlier names Google AdWords and Bing Ads.

Last updated: October 7, 2026