In Google Ads, when is cost per thousand impressions (CPM) bidding not available as a bidding option?

Introduction / Context:
Google Ads offers different bidding models, including cost per click, cost per conversion, and cost per thousand impressions. However, not every bidding model is available for every network type. This question tests whether you know where CPM bidding can and cannot be used.

Given Data / Assumptions:

• CPM bidding pays for every thousand impressions rather than for each click.
• The Google Ads system supports both Search and Display networks.
• Different networks have different recommended bidding strategies.
• We need to identify the situation where CPM bidding is not permitted.

Concept / Approach:
CPM bidding is designed for brand awareness and is associated with the Display Network, where measuring impressions makes sense. On the Search Network, the main focus is on intent driven clicks, so Google does not allow pure CPM bidding there. Instead, advertisers use cost per click or other performance based bids for search campaigns.

Step-by-Step Solution:
1. Recall that CPM bidding is a Display Network focused model and is not used for search campaigns. 2. Understand that when a campaign is opted into the Search Network, the platform expects click based or conversion based bidding. 3. Review the answer choices and look for the option that explicitly mentions the Search Network as the condition. 4. Option a states that CPM bidding is not available when your campaign is opted into the Search Network. 5. Confirm that the other options describe conditions where CPM bidding can still be available, such as display targeting or device variations.

Verification / Alternative check:
If you create a Display Network only campaign in the Google Ads interface, CPM bidding is available as one of the options. If you create a Search Network only campaign, you will not see CPM as a valid choice. This direct observation confirms the network limitation described in the correct answer.

Why Other Options Are Wrong:
Option b is wrong because CPM is allowed on Display Network only campaigns. Option c is incorrect because device type does not by itself block CPM bidding when you are on Display. Option d is also wrong because image ads are common on the Display Network where CPM is often used.

Common Pitfalls:
Learners sometimes assume that any campaign with images must use CPM bidding, which is not always true; CPC bidding is also possible on Display. Another mistake is to think that CPM could be used on Search for brand awareness, but Google restricts this model to Display for reasons of auction design and user experience.

Final Answer:
CPM bidding is not available when your campaign is opted into the Search Network.