Questions: Your home decor client wants to start running mobile ads within their current campaign. Some creatives are already mobileoptimized and may be already appearing across mobile websites. What's the first thing they should check within their Campaign Manager 360 account to make sure of delivery? They should modify their existing desktop display campaign within Campaign Manager 360. They should set up their campaign creatives in Campaign Manager 360 for mobile-friendly sizes and formats. They should examine their campaign trafficking settings in Campaign Manager 360 to see if their ads are mobilefriendly. They should configure their account in Campaign Manager 360 to include mobile devices, tablets, and mobile apps.

The answer is the third one: They should examine their campaign trafficking settings in Campaign Manager 360 to see if their ads are mobile-friendly.

Explanation for each option:

1. They should modify their existing desktop display campaign within Campaign Manager 360.

   • This option is not the first step. Modifying the existing desktop campaign might be necessary later, but initially, they need to ensure that their current settings support mobile delivery.

2. They should set up their campaign creatives in Campaign Manager 360 for mobile-friendly sizes and formats.

   • While having mobile-friendly creatives is important, the question states that some creatives are already mobile-optimized. Therefore, the first step should be to check the settings to ensure these creatives are being delivered correctly.

3. They should examine their campaign trafficking settings in Campaign Manager 360 to see if their ads are mobile-friendly.

   • This is the correct first step. By examining the campaign trafficking settings, they can ensure that the campaign is set up to deliver ads to mobile devices. This includes checking targeting options and ensuring that mobile inventory is included.

4. They should configure their account in Campaign Manager 360 to include mobile devices, tablets, and mobile apps.

   • This might be necessary if the account is not already configured to include mobile devices, but it is not the first step. The first step is to check the current campaign settings to ensure they support mobile delivery.

Summary: The first thing the client should do is examine their campaign trafficking settings in Campaign Manager 360 to see if their ads are mobile-friendly. This ensures that the campaign is set up to deliver ads to mobile devices effectively.