“Search Engine Marketing” was once was used as an umbrella term to encompass
both SEO (search engine optimization) and paid search activities. Over time, the
industry has adopted the SEM acronym to refer solely to paid search.
At Search Engine Land, we generally use SEM, PPC and/or “Paid Search” to refer to
paid listings, with the longer term of search marketing used to encompass both SEO
and SEM. Below are some of the most common terms also used to refer to SEM
Paid search ads
Paid search advertising
PPC (pay-per-call) – some ads, particularly those served to mobile search
users, may be charged by the number of clicks that resulted in a direct call
from a smartphone.
CPC (cost-per-click) *
CPM (cost-per-thousand impressions) *
Most search ads are sold on a CPC / PPC basis, but some advertising options
may also be sold on a CPM basis.