The conversion rate for Google AdWords is a critical measure in determining how efficiently a Web site promotes itself with pay-per-click campaigns.

Conversion rate is a way of measuring how much business is generated by Web site visitors. If a site uses AdWords to deliver 100,000 impressions in search engine results, and 2 percent of those impressions resulted in a click, the site would have 2,000 visitors from AdWords. If 5 percent of those 2,000 visitors click on an ad on the site or made a purchase, the AdWords conversion rate would be 5 percent.

Click-through rate and conversion rate are tightly bound together.

Six tactics that improve the click-through rate also can improve the conversion rate because they reach customers effeciently:

1. Select highly targeted keywords
2. Optimize the landing page
3. Test the ad copy
4. Remove unproductive keywords
5. Manage the overall campaign
6. Measure the results

Select highly targeted keywords. Effective keyword selection starts with using the AdWords keyword tool to identify keywords and keyword phrases that most closely the page that the campaign is targeting. A three-word phase is optimal because one or two words usually have the most competition and the highest cost, while four or more words in a phrase are hard to find and usually have a small number of impressions. The more specific the phrase, the more targeted and effective the result.

Optimize the landing page. Once a phrase is chosen, landing page optimization requires that the page have the same phrase, usually in the title, description, headline and body of the article, among other places.

Test the ad copy. Always start with at least two ads for the phrase and look at the resulting click-through rates one to two weeks after the launch of the campaign. Pause or delete the poor performer and create a new one. This is called A/B testing and can have a major impact on conversion over time.

Remove unproductive keywords. After two or more weeks, look at which keywords appear the fewest times and have the lowest click-through rates. Pause or delete the poor performers and search for new ones with the keyword tool.

Manage the overall campaign. A single AdWords campaign can have multiple ad groups, and a single AdWords account can have multiple campaigns. Paying regular attention to each ad group and campaign will result in higher conversion rates across all of the activity.

Measure the results. Use a spreadsheet to analyze and record each campaign and ad group at least monthly. Look for weak performers and concentrate efforts there.

Conversion rates vary greatly from one keyword to the other, with some exceptionally targeted and effective keywords generating double digit click-through rates. But an account should be able to exceed an average click-through rate of more than 2 percent for all campaigns and ad groups.