Is a Smaller Influencer Always More Effective?

Imagine you're about to launch a new running shoe. On your list are a running coach with twenty thousand followers and a lifestyle creator with two million. The first speaks to a community likely to be interested in the product; the second has a far larger audience. Which one should you work with?

Before deciding, you need to define the goal of the campaign. Do you want people to ask questions about the product, get to know your brand, or buy the shoe? The answer determines which data you should prioritize when choosing an influencer.

BraindPower, which offers AI-powered influencer analysis, helps you evaluate candidates not just by follower count but also by audience characteristics, engagement data and brand fit.

In influencer marketing, engagement and purchase intent are different things

A study by Mojtaba (Moji) Barari and colleagues, published online in 2025, brings together the results of 135 experiments from 71 academic studies. The researchers compare influencer content with other forms of brand promotion and examine under which conditions consumer responses change.

In this assessment, small and mid-sized influencers are found to be more effective on engagement such as likes and comments, while large influencers are more effective on purchase intent. However, the study classifies follower counts below one million as small and mid-sized, and those above one million as large. So we can't read the finding directly as "a micro-influencer always brings more engagement."

Purchase intent doesn't mean a completed sale, either. Someone may say they want to buy a product, then find the price too high and change their mind. Likes and comments show the reaction to the content, while sales records let you assess whether the campaign turned into purchases.

Smaller influencers can have an advantage in sales too

A sales-focused study by Maximilian Beichert and colleagues, published in the 2024 issue of the Journal of Marketing, examines influencer collaborations of direct-to-consumer brands. The researchers analyze sales data of about 1.9 million units from a European clothing brand, along with three field studies. Taking collaboration costs into account, they find that working with influencers who have fewer followers delivered a higher return on investment under the conditions studied.

The yardstick here is the result achieved relative to the budget spent. Even if one influencer brings in more sales, if their fee is very high, another option that brings fewer sales may be more efficient for the budget.

This study shows that small accounts can have an advantage in sales-focused campaigns, but it doesn't guarantee the same result for every product and campaign. The fact that purchase intent and budget efficiency are different measures also helps explain why studies can reach different conclusions. More engagement, higher purchase intent and more efficient sales are not the same success metric.

How the content is told also affects influencer choice

A study by Simone Wies and colleagues covering 802 Instagram campaigns shows that the relationship between follower count and engagement can vary with how much the content is personalized. In the data examined, engagement first rises as follower count grows, then falls. When an influencer adapts the content to their own style and audience instead of repeating the brand's ready-made text, this relationship changes, and the relative effectiveness of small and large accounts compared with mid-sized ones can increase.

In the running shoe example, this could mean leaving room for the coach to use the product in their own training and describe their experience. When choosing, it also helps to look at a person's previous collaborations. How do they present the product? What questions do followers ask? Are the answers adequate? This review clarifies what you can expect from the collaboration.

Base influencer selection on data with BraindPower

To make this assessment, you need to see candidates' data side by side. BraindPower's influencer marketing module lets you examine creators by criteria such as category, platform, audience demographics and engagement rate. That way, you can compare accounts of different sizes using the same criteria.

In the running shoe campaign, for example, you can identify candidates who create sports content and see how closely their audiences overlap with the customers you're targeting. BraindPower's brand fit assessment considers factors such as audience overlap, content category and storytelling style together. Engagement history and follower growth help you look beyond a single successful post and examine the account's performance over time.

You can then evaluate this information together with the fee quotes you receive from candidates. If your goal is sales, you need to compare the sales you track through campaign-specific links or discount codes with the cost of the collaboration. Tracking methods like these are also used in the research to evaluate the sales results of influencer collaborations.

You can use the comparisons in BraindPower for candidate selection, and your own sales records to assess the campaign's commercial outcome. That way, you consider influencer analysis and sales performance together without substituting one for the other.

The yardstick for your next collaboration also becomes clearer. You ask not only how many followers an account has, but who it reaches and what you get for the budget you set aside.

The right question isn't just "Small influencer or big influencer?" but "Which creator is a better fit for my brand, for which goal?" To find the right influencer for your brand, you can explore BraindPower's influencer marketing module.