Why is it recommended to use the Ad Preview and Diagnosis tool instead of performing repeated Google searches to check whether your ads are running?

Introduction / Context:
Many advertisers want to see their own ads on Google search results. However, typing the same queries repeatedly into the live Google search page can affect performance metrics and can give a misleading impression about how often ads are shown. Google provides the Ad Preview and Diagnosis tool to help with this. The question asks why this specific tool should be used.

Given Data / Assumptions:

• We want to verify that ads are eligible and see how they look in search results.
• We do not want to damage clickthrough rate or skew impression data.
• The Ad Preview and Diagnosis tool is available inside Google Ads.
• Normal searching on Google may generate impressions without clicks.

Concept / Approach:
Every time an ad is shown on a live search results page it counts as an impression. If you keep searching for your own keywords and do not click on your ads, that raises impressions but not clicks, which lowers clickthrough rate. Lower clickthrough rate can harm Quality Score and long term performance. The Ad Preview and Diagnosis tool simulates the results page for selected keywords, locations, and devices without registering actual impressions in your campaign statistics.

Step-by-Step Solution:
1. Identify that the goal is to see how ads appear without harming campaign performance. 2. Recall that live searches where you do not click your own ads will lower clickthrough rate over time. 3. Understand that the Ad Preview and Diagnosis tool was designed to avoid this by not adding impressions. 4. Look for the option that mentions seeing ad appearance without affecting impressions or metrics. 5. Option a states that the tool shows ads on a results page without adding impressions or changing clickthrough rates, which fits the official explanation.

Verification / Alternative check:
If you open the Ad Preview and Diagnosis tool, you can enter a keyword, location, language, and device and see a simulated Google search results page. The tool will tell you whether your ad is eligible and why it may or may not show. The interface also makes it clear that this preview does not count as an impression in your reports, confirming the advantage described in the answer.

Why Other Options Are Wrong:
Option b is wrong because the tool does not automatically raise bids; bidding decisions remain under your control. Option c is incorrect because competing advertisers are not paused or disabled in any way; the tool simply simulates results. Option d is also wrong because the tool does not modify campaign budgets.

Common Pitfalls:
A common mistake is to repeatedly search for your own ads and feel concerned when they do not show every time. Auctions are dynamic and ads may not always appear. Constant self searching can hurt performance, so using the diagnostic tool is the safer and recommended method.

Final Answer:
You should use the Ad Preview and Diagnosis tool because it shows how your ads appear without generating extra impressions or lowering your campaign clickthrough rates.