The Impact of Influencer Mix Strategies on Engagement Rates: A Difference-in-Differences Analysis of Instagram Marketing Campaigns

Abstract

The rise of social media has positioned influencer marketing as a cornerstone of contemporary brand strategies, yet the comparative effectiveness of microinfluencers (10,000–99,999 followers) versus macro-influencers (≥100,000 followers) remains inadequately debated. This study extends the discourse by introducing a novel "mix strategy"—where brands collaborate with both micro- and macro-influencers and evaluates its impact on engagement rates compared to single-influencer approaches. Leveraging simulated data from the "2022 Social Media Influencers" dataset on Kaggle, this research applies a Difference-in-Differences (DID) model to estimate the causal effect of the mix strategy. The eventual findings reveal that the mix strategy of one micro- and one macro- influencer significantly outperforms the single-influencer strategy, which could increase the engagement rates by approximately 1.2 percentage points. This research advances influencer marketing literature by offering empirical evidence of the mix strategy’s efficacy and provides actionable insights for optimizing brand marketing strategies on social media and future influencer endorsement plans.