What's the Difference Between SEO and SEM?
By Stephen Bucaro
SEO (Search Engine Optimization) is the practice of manipulating aspects of a
webpage so that, when a user enters a particular term or phrase in a search
engine, that webpage shows up as close as possible to the top of the results
returned by a search engine.
Since about two-thirds of all searches are entered into Google's search engine,
and since Google's robot ranks webpages based upon specific rules specified
by Google's engineers, SEO is in fact the act of gaming Google's search robot.
It's not easy to game Google's search algorithm because they keep changing it.
I wouldn't refer to these changes as updates because Google'es engineers have
implemented some algorithms that didn't work out and they had to back out of them.
But there are some aspects of SEO that are always critical to a webpage's
position in any search engines results.
1. The title within the page's html title tag.
2. The description within the page's description meta tag.
3. The title within the page's header tags.
4. The frequency with which the keyword or phrase appears within the page's contents.
In the past, some webmaster's have tried to game the search algorithm by excessively
repeating the search term or search phrase within the page's content, but Google's
recent search algorithmís are smart enough to detect this and consider it search
engine spam, and penalize the page's rank within search results.
Another important parameter used to rank a webpage is the number of links
from other webpages that point to the page being analyzed. In the past, some
webmaster's have tried to game the search algorithm by trading links with other
webmaster's, but Google's recent search algorithmís are smart enough to detect
this, mark it search engine spam, and penalize pages involved in link trading schemes.
Other important parameters used to rank a webpage is the uniqueness of the
page's content, and the authority and trust of the website hosting the page.
Because Google's search algorithm is so complex and is a moving target, many
Internet organizations employ SEO professionals.
SEM (Search engine marketing) involves increasing a page's rank in search results
by paying a search engine to deliberately increase it's position in the search results.
If a search engine were to do this clandestinely, it would degrade the quality of
the results, so search engines more or less clearly mark the payed results.
Another method of SEM is the purchasing of advertising. This usually involves
getting webmasters to display a banner or link on their website and paying them
a small commission every time someone clicks on it (Pay Per Click or PPC).
In the past, some webmaster's have tried to game PPC by repeatedly clicking on a
banner or link themselves, or by enlisting their friends to click on it. Most advertisers
who use PPC have algorithms that detect click fraud and take counter measures
to deal with it. For example repeated clicks from the same domain will not be counted.
a high number of clicks on an advertisement without an additional action, such as
a sign up or purchase will not be counted.
Other methods of SEM include running contests and promoting a webpage or
website offline, such as in printed advertising or on television. SEM is any method
of creating a buzz which results in increasing the demand for a webpage or website.
The activities of SEO and SEM are relatively new and therefore not yet precisely
defined. Most sources consider SEM to be part of SEO because they employ SEO
experts that frequently include SEM in their services. But recently you can also
hire SEM's (Search Engine Marketers) that might also include SEO in their services.
So don't be confused if you hear the terms used interchangeably.