Influencer tiers are informal but widely used shorthand for follower count ranges: nano (roughly 1,000 to 10,000), micro (roughly 10,000 to 100,000), mid-tier or macro (100,000 to 1,000,000), and mega or celebrity (over 1,000,000). The exact cutoffs shift depending on who is drawing them, but micro sits consistently in the tens of thousands range.
Micro influencers are attractive to brands for a specific reason: engagement rates tend to fall as follower counts rise, so a micro influencer's smaller, more niche audience often engages harder per follower than a much larger account does. A brand deal with a micro influencer pays for that audience and trust, and the deliverable is a post to the creator's own following, the core difference from a UGC creator, who is paid for the content alone and needs no following at all.
Socialync's job board covers both models. Every campaign sets a floor and a brief, and creators whose connected accounts clear the floor can apply, whether the job is a post to the creator's own audience or a UGC asset the brand plans to run as an ad.