Analyze the following scenarios involving adjustments in paid marketing experiments to achieve Product-Market-Channel Fit:
- Scenario I: A beauty brand notices a high CPM in their Facebook Ads campaign. They switch to a different audience segment with lower competition to reduce CPM.
- Scenario II: An online bookstore has low CTR on Google Ads. They decide to use the same ad creatives but increase the budget to boost visibility.
- Scenario III: A fitness app finds its Google Ads have high ICP% but low conversion rates. They modify the landing page to better reflect the ad's messaging and USP.
- Scenario IV: A food delivery service experiences low conversion rates and ICP% in their Instagram Ads. They change their ad format from images to videos to increase engagement.
Select the scenario(s) that demonstrate effective adjustment strategies in paid marketing experiments.