Email signature marketing, done honestly.

The click on a signature banner is fundamentally different from a click on a display ad or a cold outbound link. The recipient already opened the email. They know the sender. They're two paragraphs deep in a reply about a deal, a support ticket, an intro. Then they see: "Wren is hiring a designer in Berlin." One click, in context, from someone they trust.

That's what makes the channel work despite tiny raw numbers. You will not get thousands of clicks a month from signatures on a 30-person team. You will get 30–70 warm clicks that convert at 4–8× a cold visitor, from a channel that costs you nothing to run because the emails were going out anyway.

A 30-person team where roughly two-thirds of people send meaningful outbound (sales, support, recruiting, execs) sends 5,000–8,000 personal emails a month. Even at the low end of a plausible click rate, that's the channel size:

Small in isolation. Meaningful when you remember these clicks are already past the "does this person know me" filter that eats 99% of paid traffic.

One image. One message. One link. That's it. The instinct to cram in a QR code, three logos, and a paragraph of copy is what makes signature banners look like the mid-2000s. What works in practice, ranked by conversion from our own campaign data:

1. Concrete offer with a deadline. "Free 30-day trial — ends Dec 15." Beats "Try our product" by roughly 3×.
2. Named event with a date. "Live demo — Thursday 11am PT." Recipients calibrate instantly on whether it's relevant.
3. Hiring pushes. Consistently the highest-converting banner category on Wren — because your recipients often know the perfect candidate.
4. Case study or customer story. Named customer + one number. "How Acme cut onboarding from 3 weeks to 4 days."
5. Content with a specific claim. "The 7 email-signature mistakes that cost you clicks" beats "Read our blog" every time.

What consistently underperforms: generic brand banners ("We're Wren!"), product feature announcements without an offer, and anything that requires three seconds of squinting to understand.

Change the banner every 2–4 weeks. Less often and the channel goes stale for people who see the same recipients repeatedly; more often and you never give a campaign long enough to build clicks. A workable annual rhythm:

• • 60% of the year on your always-on offer (free trial, demo booking, hiring page).
• • 25% on active launches and campaigns — a new feature, a customer story, a webinar.
• • 15% on time-boxed pushes — hiring sprint, event week, seasonal offer.

The reason this only works with a real signature platform: without one, each change means 30 people re-pasting HTML into their mail client. In practice that means you swap the banner once, and never again.

Measure clicks per campaign. That's the honest number. Attribute with a UTM (utm_source=signature plusutm_campaign=<name>) or a redirect that logs the hit.

Ignore email opens. Signature-embedded pixels are proxied through Gmail's image cache and Apple Mail Privacy Protection, so open tracking is meaningless. Anyone selling you "signature opens" is selling noise.

Attribute downstream, don't overclaim. Signature clicks rarely convert on the first touch — they're a warm assist, not a last-click channel. Look at whether pipeline sources include "signature" as a touchpoint, not whether it drove the demo booking on its own.

1. 1. Everyone runs a different banner. "Personalisation" sounds good until you realise it's the same as running 30 different one-person campaigns. Pick one banner, run it across the team, measure it, then move on. Uniformity is the whole reason this works.
2. 2. Hard-coded image URLs. If q4-launch.png is baked into every teammate's signature, next quarter's banner requires 30 re-installs. The banner URL has to be stable and the image behind it has to be swappable — otherwise you'll change it once, then never again.
3. 3. Hosting the image on Google Drive or Dropbox. Gmail's image proxy fetches banner URLs anonymously. If the file is behind a login wall, recipients see a broken image. Host on a real CDN or on a signature platform that hosts assets for you.
4. 4. No click tracking. Without a UTM or a redirect, you have no signal on which banner worked. The whole thing degrades into "did it feel like people were clicking" — and nobody will ever be able to justify keeping the channel alive.