The Role of Quality Score and Ad Rank in Search Engine Marketing

Search engine marketing is more than bidding for relevant keywords. To be successful an advertiser needs develop quality landing pages and engaging content.


What is Search Engine Marketing?

Search engine marketing (SEM) is a form of advertising that that involves bidding on keywords so that a specific ad will appear on the results page. It is commonly referred to as PPC (pay-per-click) advertising, and is popular on Google and Bing search engines.


Here is an example of search engine marketing from the searcher’s perspective:

pizza search query with examples of Google AdWords ads

For this example, the search query was “pizza,” which also happens to be the keyword. If instead of “pizza,” a searcher entered “where can I buy pizza near me,” the search query would be that entire piece of text. Advertisers may bid for a single keyword (which may be a word in a search query), or a keyword phrase (which may match an entire search query).

When the keyword was entered into the Google search bar, an auction took place. In this example Pizza Hut and Dominos were two of the bidders competing for their ad to appear.

How Does Bidding Work in Search Engine Marketing?

To explain this process, it’s necessary to go back in time, to before the search occurred.

Well before the search for “pizza” began, Pizza Hut, Dominos and a number of other companies set up a Google AdWords account, and created a campaign targeting people searching for “pizza.” These companies can target people searching in specific geographic locations, by what type of device they were using to perform the search, or a number of other factors.

Within each campaign are a number of Ad Groups, which are commonly differentiated from each other based on advertising strategy, or the web page searchers visit when they click the ad (also known as a landing page). Each Ad Group contains a set of keywords and ads.

In Google AdWords, an Ad Group looks like this:

Ad Groups look like this in Google AdWords

In Google AdWords, an ad looks like this:

Ads look like this in Google AdWords

Keywords are words or phrases a company believes searchers will use when trying to find the product being offered. Essentially, an advertiser is attempting to guess (though it should more appropriately be called a well-researched, educated guess) what someone would search for if they knew what they wanted, but weren’t sure where to buy it. For each keyword, a bid is placed which represents the maximum amount an advertiser is willing to pay for their ad to appear when a person searches for that keyword.  


In Google AdWords, keywords look like this:

Keywords look like this in Google AdWords


Every advertiser performs the actions, which leads to an auction when multiple advertisers bid for the same keyword. If two or more advertisers bid for the same keyword, an auction occurs, but it’s not always the highest bid that wins.


How Does Google Determine Ad Placement?

Google, like most popular search engines, uses an algorithm and ranking system to decide which ads will appear on the SERP (search engine result page). The bid is only one factor that is considered.


Here is how Google determines which ads to show:

There are two key metrics which are measured to determine where an ad will rank (Ad Rank). The CPC (cost-per-click) bid and the Quality Score are both evaluated when a search is performed. The keywords with the best combination of these two factors will earn the highest Ad Rank.

The CPC bid is the maximum amount an advertiser is willing to pay when a searcher clicks their ad. The Quality Score is a measure of multiple factors.

Here is how Google determines the Quality Score of a keyword:

A keyword’s Quality Score is measured by factoring in:

  • The relevance of the keyword, ad and landing page’s URL, to the search query.
  • The quality and relevance of the landing page to the search query.
  • The past performance of the campaign, including historical CTR (click-through-rate), previous Quality Scores and overall effectiveness of the campaign.

Based on these two metrics, Google determines the rank of every ad competing for the same keyword. Similarly, because both of these metrics have the potential to change from minute-to-minute, Ad Rank can constantly fluctuate.

Why is Ad Rank Important?

Ad Rank is important because people rarely view the second or third search results page; and they generally click the first result.

Based on one study by Chitka, the search result with the top position received nearly 33% of the total traffic. The second position received 18% and third result gathered 11% of the potential traffic. After that the results degraded quickly.

 In total, the results on the first page received 92% of all the potential traffic, while the second page received less than 5%, and the third captured 1%.

From this research it’s clear that placement is critical, and explains why competition is tough for so many industries. Every business is fighting to gain the best Ad Rank because the top spot will often capture the most traffic.

What Determines a Good Search Engine Marketing Strategy?

Search engine marketing is more than choosing keywords and bidding more aggressively than competitors. The Quality Score is a measure of overall campaign performance, relevance and landing page quality. An ad gains the top placement because the advertiser addressed all factors that are measured by the Quality Score. This often requires the cooperation of multiple people within a business, or one person who knows how to do it all.


Search Engine Marketing is a mix of:

  • SEO (search engine optimization)
  • Keyword research
  • Market research
  • Advertising strategy
  • Web development
  • Web design
  • Content marketing


To be successful with SEM, an advertiser needs to:

  • Research and understand their target market, including how they search
  • Research and discover the keywords people will use to search for specific products or services.
  • Build an advertising strategy that targets the most qualified searchers at the exact moment they’re ready to make a purchasing decision.
  • Develop a high-quality landing page that is relevant to a specific set of targeted keywords.
  • Design a landing page that is engaging and clearly communicates its purpose and value to visitors.
  • Incorporate targeted keywords effectively and organically throughout the landing page.
  • Create engaging, interesting and valuable content for the landing page to keep visitors on page longer and encourage them to return.