Showing up in a higher position will not benefit your Quality Score.

Although higher-ranked ads may typically earn better clickthrough rates, Quality Score is normalized to compensate for performance differences resulting from ad position.

Your ad conversion rate does not affect your Quality Score.

Some advertisers using AdWords conversion tracking mistakenly believe that they should set an easy conversion event on their landing pages to artificially boost their conversion rates. In reality, this will not actually have any effect on your Quality Scores. Feel free to use conversion tracking to meet your clients' needs and don't worry about its impact on your Quality Scores.

Google does not keep track of your landing page Quality Score history.

We've heard some concern from advertisers who think their current Quality Score is being lowered by previous landing pages' Quality Scores. However, Google only uses the most recent check of your landing page to determine its relevance and quality.

A few bad days of test performance will not ruin your Quality Scores.

In order to optimize your clients' accounts, we encourage you to run targeted tests on your bids, creatives, and keywords. These small tests are a useful way to measure the impact of changes before applying them more widely. You should carefully track the performance of your experiments. If you find that the changes you've made don't perform well after a few days, you can revise your experiment or delete those changes and the short term impact on your Quality Score will soon be outweighed by the positive performance you have accrued in the rest of your client's account.

Changing a keyword from broad to exact match will not improve its Quality Score.

With broad match, your ads may show on variations of your keywords. However, ad performance on these variations won't affect your keywords' Quality Scores. For example, say your ad group contained the broad-matched keyword resolution. Your ad could potentially show when a user searched for new year's resolution or conflict resolution, although its performance in these instances would have no impact on Quality Score. The keyword's Quality Score would only be affected by how your ad performed on the search term resolution, since it exactly matches the keyword. Changing a broad-matched keyword to an exact match, therefore, won't improve its Quality Score.