SEM

SEM stands for Search Engine Marketing and covers marketing on the search engines' result pages. The term originally held both paid advertising and SEO, but in everyday use most people now say SEM about the paid part: ads in Google Ads and Microsoft Advertising, also called PPC or paid search.

How SEM works

An advertiser picks the keywords it wants visibility on and bids in an auction. A winning ad sits at the top of the page among the paid search results, marked "Sponsored", and the advertiser pays per click. The price depends on competition for the individual keyword and on quality score, Google's assessment of how relevant the ad and its landing page are. A high bid cannot buy its way out of weak content.

The strength of SEM is control and speed: visibility on a keyword can start tomorrow, the budget can be steered to the cent, and it all switches off when the campaign ends. The weakness is the same mechanic from the other side, since the visibility stops the moment the budget does.

The interplay with SEO

The two disciplines complement each other. Ads can cover the keywords where organic rankings have not arrived yet, while SEO builds the lasting visibility, and search term data from an ad account is strong raw material for keyword research, because it shows which queries convert. SEM buys attention here and now; SEO decides whether a company is found without paying for it.