Generate a framework for assessing the effectiveness of an influencer collaboration after its completion. Start by collecting data on key performance indicators such as #engagement rates, #follower growth, and #web traffic increase. Compare these metrics to pre-collaboration benchmarks, such as #previous data. Analyze the qualitative impact, considering factors like #audience sentiment and #brand perception. Discuss the ROI by evaluating the costs incurred, which were approximately #costs, versus the benefits gained, including #benefits. Identify areas of improvement and propose recommendations for future collaborations, such as #recommendation 1 or #recommendation 2. Additionally, describe how to solicit feedback from the collaborating influencer to gain insights and strengthen future partnerships, for example, by asking #feedback questions.