Most influencer outreach fails before the creator even opens your email. Often, the reason is the subject line.
For the rest of the process, see how to contact influencers.
Creators get brand emails every day. They decide in a second which ones to open, and they decide it by the subject line. If it doesn't tell them what's in it for them, your carefully written pitch never gets read.
I recently came across a subject line on Reddit that I consider almost perfect. It's short, it's honest, and every word in it does a job. I now use it myself, sometimes in a shorter version. Before that, my subject lines were usually the creator's account name x the brand name, or a faceless "Collaboration opportunity." Below, I'll break it down part by part, show how to adapt it to any type of collaboration, and explain how to test it.
This is part one of two. Once the email is opened, the body has to do the rest: that's covered in the influencer outreach email template I recommend.
The influencer outreach subject line formula
Here's the subject line:
[PAID] {{creator_name}} x {{your_brand}} Sponsorship Opportunity
It has four parts, and each one answers a question the creator asks before opening a brand email:
What kind of deal is it? The tag in brackets.
Is this email really for me? The creator's name.
Who's writing? Your brand or product.
What's on offer? The type of opportunity.
I. The deal tag: [PAID]
[PAID] tells the creator immediately that this is a paid collaboration. It's the exact keyword creators look for first. It grabs attention fast and doesn't waste anyone's time.
If your collaboration isn't paid, say so just as clearly, in brackets:
[GIFTED]
[COMMISSION]
[FREE PRODUCT]
[EVENT INVITE]
Don't hide the terms. If a creator doesn't work on commission, no subject line trick will convince them otherwise. And if they find out in the third email that it's a barter deal, you've both wasted your time.
I've sent affiliate offers with the commission tag right in the subject line. The open rate was lower, as you'd expect. But the replies were better: creators answered straight away with a clear yes or a clear "no, we don't work like that." No back-and-forth, no wasted time.
And a "no" isn't always the end. If you really want to work with that creator and your budget allows it, you can come back with a different offer, for example a paid post instead of an affiliate deal.
What about caps? Writing the whole subject line in capitals is a bad idea: spam filters don't like it. A short tag like [PAID] is acceptable. If you'd rather play it safe, write it in normal case: [Paid collab].
II. The creator's name: {{creator_name}}
The creator's name is your personalization. It makes the email feel intentional rather than mass-sent.
You have two options: the creator's first name or their handle. I've tested both, and the first name gets a better open rate. A handle in the subject line gives the game away: it's obviously a variable, and nobody bothered to find out what the creator is actually called. A first name shows you did.
If you send from HypeAuditor, you don't have to type names by hand: insert the variable into the subject line, and it's filled in for every recipient. Here's how variables work in HypeAuditor Outreach.
III. Your brand: {{your_brand}}
This is where you show who you are, with a bit of nuance. Use whichever name the creator is more likely to recognize:
Your brand is recognizable: use the brand name.
Your product is more famous than the brand: use the product name instead.
Your brand has a very large product line: name the specific product or category that's most relevant to this creator, for example Nike Running or Walmart Kids' Toys.
The last option does double duty. It makes the offer feel personal and shows the creator that it fits their niche and audience before they open the email.
IV. The offer: Sponsorship Opportunity
You can keep this part as it is or swap it for something that matches the deal:
Paid collaboration: "Sponsorship Opportunity" works perfectly.
Gifted or commission-based collaboration: soften it to "Partnership Opportunity" or something similar.
"Sponsorship" signals money. Using it for a gifting campaign creates an expectation the email can't meet.
Subject line examples for every type of collaboration
Here's how the formula adapts to different deals. The brand names are made up; swap in your own.
Collaboration type | Subject line |
Paid post | [PAID] Mia x GlowLab Sponsorship Opportunity |
Paid, large product line | [PAID] Mia x GlowLab Sunscreen Sponsorship Opportunity |
Gifting | [GIFTED] Mia x GlowLab Partnership Opportunity |
Affiliate program | [COMMISSION] Mia x GlowLab Partnership Opportunity |
Free product for review | [FREE PRODUCT] Mia x GlowLab Partnership Opportunity |
Event | [EVENT INVITE] Mia x GlowLab Launch Party |
Safer-caps version | [Paid collab] Mia x GlowLab Sponsorship Opportunity |
Notice that the structure never changes. Only the tag, the name of the brand or product and the offer do. Full emails for each of these deals are in our influencer outreach templates.
Length, emojis and follow-up subject lines
How long should the subject line be?
The limit is the point where a phone cuts the subject line off. On an iPhone, the Gmail app shows about 37 characters and Apple Mail about 48, according to tests by EmailToolTester.
Your subject line can be longer, but the important part has to fit before the cut. Whatever gets cut off should be a bonus: if it disappeared completely, the subject line should still work. In the formula, the tag, the creator's name and your brand go first for exactly that reason. "Sponsorship Opportunity" is the part a phone can afford to hide.
Can you use emojis in the subject line?
It depends on your volume:
Targeted emails to a few creators, small overall volume: an emoji is fine. Just don't overdo it.
High-volume cold outreach: don't use emojis at all. They're one of the spam signals, and if your sending is already close to the edge, they can tip it over.
What subject line should follow-ups have?
Follow-up subject lines are worth testing too. One approach I like: keep the same subject with "Re:" for the first follow-up, then use a different subject for the second. The second one looks like a new email, and a different angle may be the one that catches the creator's attention.
What to avoid in an influencer outreach subject line
A subject line can kill an email in two ways: the creator ignores it, or a spam filter hides it. Avoid both:
The whole subject line in caps. A short tag is fine. "COLLAB OPPORTUNITY FOR YOU" is not.
Dollar signs instead of facts. "$300 per post" is a fact. "$$$ opportunity" looks like spam.
Clickbait and pressure. "Open now," "Once in a lifetime chance" or "Urgent" make the email look like a scam.
Vague subject lines. "Quick question" or "Collaboration" tell the creator nothing, so they have no reason to open.
Hiding the terms. Saying "Sponsorship" for a gifting campaign gets you an open, but not a deal.
Emojis in high-volume sends. In a one-off email, one emoji is fine. In bulk outreach, emojis are a spam signal.
How to test your subject line
Steal this formula, test it, tweak it, and your open rates will thank you. Here's how to test it properly:
Change one thing at a time. For example, [PAID] against [Paid collab], or the brand name against the product name.
Split your list in two. If your outreach tool has A/B testing, use it. If not, split the list in half by hand and launch the two versions as two separate templates, from the same mailbox, at the same time.
Wait at least a day. Then check again after 3 and 7 days: outreach metrics usually stabilize within a week.
Compare open rates. Around 20% is normal for creator outreach, 10% signals a problem, and 50–60% is a strong result.
One caveat: open rate is inflated by bots and privacy features like Apple Mail Privacy Protection, so treat it as a direction, not a verdict. If one version also brings more replies, that's your winner. More on that in my guide to influencer outreach metrics.
And if the open rate is low on both versions, the subject line may not be the problem at all. Check your deliverability first.
FAQ
What is a good subject line for influencer outreach?
A good influencer outreach subject line follows four parts: a deal tag, the creator's name, your brand and the offer. For example: [PAID] {{creator_name}} x {{your_brand}} Sponsorship Opportunity. It tells the creator what the deal is and who it's from before they open the email.
Should you say "paid" in the subject line of an influencer email?
Yes. If the collaboration is paid, a tag like [PAID] or [Paid collab] at the start of the subject line is the keyword creators look for first. For other deals, use an honest tag such as [GIFTED], [COMMISSION], [FREE PRODUCT] or [EVENT INVITE].
Should you use the creator's first name or handle in the subject line?
Use the first name. In my tests, the first name gets a better open rate. A handle looks like an automatic variable, while a first name shows you took the time to find out who the creator is.
Can you use caps in an influencer outreach subject line?
Avoid writing the whole subject line in caps, because spam filters penalize it. A short tag in brackets, such as [PAID], is acceptable. For a safer option, write it in normal case: [Paid collab].
What open rate should an influencer outreach subject line get?
An open rate of around 20% is normal for influencer outreach, 10% signals a problem, and 50–60% is a strong result. Open rates are inflated by bots and privacy features, so confirm a winning subject line with reply rate as well.
How long should an influencer outreach subject line be?
The key part of the subject line should fit before a phone cuts it off: about 37 characters in the Gmail app and about 48 in Apple Mail on an iPhone. The rest can be longer, as long as the subject line still works without it.
