Before you spend a dollar, you need the full menu. Most teams reach for paid social and call it a plan. But an event is filled by a mix of channels - and the cheapest one is usually the one they ignore: their own participants. Here's every channel, grouped by how you pay for it.
Owned & organic channels
Start where the map is cheapest. The marginal cost here is near zero, so this slice should do the heaviest lifting - and email is the workhorse: it tops channel-ROI surveys year after year (Litmus pegs it around $36 back per $1 across industries - not event-specific, but the direction holds). A fast, single-event landing page with one-field forms and disciplined UTMs is what actually converts all that reach into registrations. For reminders, use whatever channel your audience actually opens: WhatsApp where it's the default business channel (APAC, India, LATAM), SMS and email elsewhere. Organic social cuts through best when employees and advocates post, not the brand page.
Paid channels
Owned channels only reach people who already know you, so to find net-new audiences you have to rent reach - and that's where the CAC climbs, so size it deliberately. And mind the unit - the benchmarks people quote are cost per lead, and a lead is not a registration. LinkedIn CPL runs ~$408 and Meta ~$142 (Sopro 2025), with search/PPC higher still - then a completed registration absorbs your landing-page conversion rate on top. Warm audiences (retargeting your own list) can land a registration for $40-50, while cold paid social typically works out to ~$200 per registration - the planning figure used throughout this series. The budget formula shows the math for converting CPL into cost per registration.
Mind the unit - it's stacked in paid's favour here. The $25 referral is already a registration, while $142 and $408 buy only a lead that still has to convert to a seat. Compared like-for-like, the referral gap is wider, not narrower.
The cost cheat sheet
One table to take to your planning doc: what a registration costs per lane, cheapest first. All planning figures - overwrite any of them with your own history.
| Lane | Cost / registration | Notes |
|---|---|---|
| Email your own list / past attendees | ~Free | Tooling + your time; the workhorse. |
| Organic social & newsletter | ~Free | Owned reach; strongest when people post, not the brand page. |
| Partner & community cross-promo | Swaps | Newsletter swaps, comp passes - cash-free reach. |
| Event listing sites | Low | Listing fees; discovery traffic you don't have to earn. |
| Retargeting your own audience | ~$45/reg | Warm paid - your list already knows you. |
| Search & PPC | ~$120/reg | Intent capture; costs scale with your category's CPCs. |
| Cold paid social (blended) | ~$200/reg | The series' planning rate; LinkedIn CPL alone runs ~$408 (Sopro 2025) - and that's a lead, not a seat. |
| Affiliate & ambassador program | ~$40/reg | Commission per registration; pay only on results. |
| Participant referral (benchmark) | ~$25/reg | Independent benchmark (Sopro 2025) - already a seat, not a lead. |
| Advocacy on a flat-cost platform | ~$0 marginal | Platform cost is flat, so each additional referral is near-free. |
These match the rates the Fill the Room simulator plays with, so the map and the game never disagree. The budget formula turns this table into a full plan.
Earned / advocacy - the multiplier
Paid buys you reach you don't keep; this channel compounds the audience you already have. It's the one most plans treat as an afterthought, and it's where the cheapest growth lives. Your participants become a volunteer marketing army:
- Speakers - the highest-trust amplifiers. Full playbook: Turn Speakers Into Your Best Recruiters.
- Attendees - the largest army; one-click sharing turns them into a flywheel. Full playbook: Turn Attendees Into a Sharing Machine.
- Exhibitors, sponsors, partners, media - the network multiplier. Full playbook: Exhibitors, Sponsors & Partners: The Network Multiplier.
Why it works: about 88% of people trust a recommendation from someone they know more than any advertising (Nielsen), and a post from a person reliably out-reaches the same message from a brand page. Earned reach is cheaper and more credible.
One nuance behind that $25: it's the market's benchmark cost for a referral. Run advocacy on a flat-cost platform and each additional referral is effectively free at the margin - which is why the simulator models these channels at $0, not $25.
The tool stack per channel
A channel is only as good as the software running it. Here's the stack per lane:
- Email: Customer.io / HubSpot / Mailchimp - personalization tokens, send-time optimization, A/B subject lines.
- Paid social: LinkedIn Campaign Manager, Meta Ads, retargeting pixels, lookalikes off your reg list.
- Landing page: single-event page, one-field forms, UTM discipline.
- Reminders (WhatsApp/SMS): WhatsApp Business API or Twilio for reminders + share nudges - WhatsApp where your audience lives on it, SMS elsewhere.
- Advocacy: Premagic runs the entire advocacy lane - every advocate type, not just attendee "I'm attending" posters: speaker, exhibitor, sponsor and partner campaigns, employee advocacy, AI avatars, previous-event photo re-engagement, price-hike pushes and colleague referrals. Every campaign gets personalized one-click share assets, share tracking, auto email/WhatsApp nudges, and per-advocate attribution.
See it on your event
Watch Premagic turn attendees into advocates.