Evaluate the following scenarios related to scaling successful channel experiments. Decide which ones align with the criteria for scaling in the context of Product-Market-Channel Fit:
- Scenario I: A company has found success with Instagram Ads at a small scale. They decide to double their ad spend each month to rapidly increase reach.
- Scenario II: An online retailer sees positive results from their SEO efforts. They incrementally increase their content production while monitoring the impact on traffic and conversions.
- Scenario III: A SaaS company's LinkedIn marketing strategy proves effective. They plan a gradual increase in ad spend, coupled with testing different audience segments and messaging.
- Scenario IV: A fitness app gains traction through influencer partnerships. They rapidly expand the number of influencers without assessing the quality and audience fit of each new influencer.
Select the scenario(s) that correctly apply the principles of scaling successful channel experiments.