1 They have been renewed multiple times by the same brand
A brand that renews a partnership does not do so out of habit — it does so because the first collaboration converted. An influencer with 2 or 3 renewals in your sector is the most reliable external validation that exists.
It is the equivalent of a verified 5-star review from a buyer. Not a promise of conversion — a proof of conversion, validated by someone who spent a budget and decided to spend it again. If the brand that renewed is well-known, the signal is even stronger: they have internal benchmarks, they compare, and they still chose to come back.
2 Their deals are in your exact sector, not just "lifestyle"
An influencer who has signed 8 cosmetic partnerships is a niche expert. An influencer who has signed 1 cosmetic deal, 2 tech deals, 3 food deals and 4 travel deals is a generalist. For a targeted beauty campaign, sector depth is worth more than audience breadth.
The audience of a cosmetic specialist has built a relationship of trust on precisely that subject. When the influencer recommends a product in their niche, the audience attributes them the legitimacy of an expert. This legitimacy does not exist for the generalist — even if their overall engagement rate is identical or higher.
3 Their partnerships are spaced out and recurring, not a burst
An influencer who publishes 10 sponsored posts per week creates a desensitized audience. The human brain adapts: after a few weeks of advertising overexposure, sponsored posts become background noise. The audience keeps liking — but stops buying.
In contrast, a maximum of 2–3 sponsored posts per week with partnerships that recur regularly signals a balanced relationship between organic and commercial content. This is the condition for sponsored posts to still have real impact on purchase decisions.
4 The brands that chose them have a positioning similar to yours
If Sézane, Jacquemus, and Rouje have all selected the same influencer for accessible premium fashion, that is a strong signal of audience consistency. Checking the positioning of past brands — not just their sector — is one of the most underused checks in influencer sourcing.
An influencer who has worked for premium brands in your niche has an audience accustomed to premium messaging. If your brand is premium, you are speaking to an audience already qualified for your price point. The reverse is equally true: an influencer with a history of entry-level deals will struggle to convince their audience of a €150 product.
5 Their history spans multiple platforms in your niche
An influencer with cosmetic deals on Instagram AND TikTok AND YouTube has built a consistent multi-channel niche audience, not an algorithm. Multi-platform consistency within the same sector is the most predictive signal of a genuinely engaged commercial community.
In contrast, a strong presence on a single platform may reflect an audience built on the algorithmic trend of the moment — followers who followed because content was pushed by the algorithm, not because they actively chose to follow someone on a specific topic.
"An influencer retained multiple times by brands in the same sector is statistically more reliable than an influencer with high engagement but no recurring deals in your niche."
Checking these 5 signs: manual vs automated method
Manual method: browse Instagram, TikTok, and YouTube archives, search on Google, check the Linktree. This approach covers approximately 60 % of partnerships and takes 4–6 hours per profile. It misses everything that is not public (stories, newsletters, events) and everything older than 6 to 12 months depending on the platform.
With Sulico: the full history is directly accessible — which brands, how many times, which platform, which period. Filtering by niche lets you find directly the influencers with the most deals in your sector, without manually searching profile by profile. See how to find influencers already proven in your niche →
Frequently asked questions
What is the difference between engagement rate and commercial proof?
Engagement rate measures audience reactions to organic content. Commercial proof measures the ability to convert an audience into buyers for a specific brand. An influencer with 4 % engagement may have zero deals in their history — or 20 successful deals in your niche. These are two independent metrics.
How to evaluate an influencer's ROI before contacting them?
Analyze their renewal history: if a brand has engaged them 3 times in 12 months, that proves their posts convert. Also check the sector consistency of their deals (always beauty, always fashion, or all mixed) and the frequency of their partnerships (no more than 2–3 sponsored posts per week = non-desensitized audience).
Can a micro-influencer really convert for an e-commerce brand?
Yes — often better than a macro-influencer in precise niches. A micro-influencer (10k–100k followers) with 8 successful cosmetic deals in the last 18 months is more predictive than a 500k account with no commercial history in your niche.
How to access an influencer's partnership history?
Manually, it is slow and incomplete (public archives, Google, Linktree). Sulico centralizes 1.2 million indexed deals: for each influencer, you see which brands have engaged them, how many times, on which platform, and in which sector.
Find influencers already proven in your niche
Filter by deal history, sector, and platform. Free access to 5 complete profiles per day.
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