Pay per click (PPC) (also called Cost
per click) is an Internet advertising
model used to direct traffic to
websites, where advertisers pay the
publisher (typically a website owner)
when the ad is clicked. With search
engines, advertisers typically bid on
keyword phrases relevant to their
target market. Content sites commonly
charge a fixed price per click rather
than use a bidding system. PPC
"display" advertisements are shown on
web sites or search engine results
with related content that have agreed
to show ads. This approach differs
from the "pay per impression" methods
used in television and newspaper
advertising.
In contrast to the generalized portal,
which seeks to drive a high volume of
traffic to one site, PPC implements
the so-called affiliate model, that
provides purchase opportunities
wherever people may be surfing. It
does this by offering financial
incentives (in the form of a
percentage of revenue) to affiliated
partner sites. The affiliates provide
purchase-point click-through to the
merchant. It is a pay-for-performance
model: If an affiliate does not
generate sales, it represents no
cost to the merchant. Variations
include banner exchange, pay-per-click,
and revenue sharing programs.
Websites that utilize PPC ads will
display an advertisement when a
keyword query matches an advertiser's
keyword list, or when a content site
displays relevant content. Such
advertisements are called sponsored
links or sponsored ads, and appear
adjacent to or above organic results
on search engine results pages, or
anywhere a web developer chooses on
a content site
