How LinkedIn InMail ads are priced
Sponsored InMail was renamed message ads in 2020; conversation ads are the multi-button version launched the same year; LinkedIn's API still labels both SPONSORED_INMAIL/SPONSORED_MESSAGE. Both are billed cost per send — you pay when the message lands in an inbox, whether or not it is opened. Each member can receive one sponsored message per 30 days, so you are bidding for a slot, not an impression. Everything below comes from Kiin Labs 2026: 1,588 campaigns, 263 accounts, $7.7M, twelve months to September 2026.
What LinkedIn InMail ads cost: the benchmarks
| Metric | Poor (bottom quartile) | Median | Good (top quartile) | Exceptional (top decile) |
|---|---|---|---|---|
| Cost per send | $0.69 | $0.42 | $0.23 | $0.11 |
| Cost per lead (lead gen form) | $495 | $200 | $85 | $32 |
| Cost per landing page click (no form) | $108 | $41 | $18 | $8 |
| Cost per booked meeting (no form, calendar) | Campaign median $221 · p25 $130 · p75 $494 (65 campaigns ★) | |||
Per-account medians, 242 accounts with 1,000+ sends; cost per lead on the 149 accounts with five or more leads. The 32× spread in cost per lead — $32 to $1,005 — is the widest of any LinkedIn format, and most of it is settings rather than copy.
Cost per send by format
| Format | Campaigns | Open rate | Cost per send | Cost per lead |
|---|---|---|---|---|
| Message ad (single message, "InMail") | 700 | 45.4% | $0.31 | $111 |
| Conversation ad (multi-button) | 888 | 38.1% | $0.51 | $347 |
Campaign medians across the panel. The gap is mostly who runs which — conversation ads are 72% of the spend and the advertisers running them are bigger, list-heavier and bid higher. Inside the same account, conversation ads cost 15% less per send (not significant) and the same per lead. Format is not a cost lever; see conversation ads vs message ads.
Cost per send by bid: you pay 62% of your bid
| Bid per send | Campaigns | Open rate | Cost per send | Cost per open | Cost per lead |
|---|---|---|---|---|---|
| Under $0.30 | 273 | 46.0% | $0.16 | $0.37 | $65 |
| $0.30–$0.50 | 370 | 40.0% | $0.27 | $0.71 | $155 |
| $0.50–$0.80 | 361 | 41.7% | $0.38 | $0.90 | $170 |
| $0.80+ | 568 | 39.5% | $0.72 | $1.86 | $421 |
The old advice — bid high, the second-price auction protects you — assumed you pay a small fraction of the bid. You pay a median 62% of it. Paired inside 119 accounts, the highest-bid campaign pays 80% more per send [+56%, +110%] and 44% more per lead [+8%, +64%] than the lowest, for an open rate difference of 0% [−3%, +4%]. Bid explains 35% of the variance in cost per send on its own; elasticity is 0.53, so a 10% higher bid is a 5.3% dearer send. Start at LinkedIn's minimum, not its recommendation. The full reversal is in how to bid on conversation ads.
Cost per send by audience size
| Target audience | Campaigns | Open rate | Cost per send | Cost per lead |
|---|---|---|---|---|
| Under 5,000 | 282 | 44.5% | $0.58 | $190 |
| 5,000–15,000 | 222 | 41.2% | $0.49 | $224 |
| 15,000–50,000 | 324 | 42.6% | $0.43 | $168 |
| 50,000–150,000 | 241 | 41.8% | $0.33 | $183 |
| 150,000+ | 297 | 39.8% | $0.26 | $147 |
Cost per send halves from the smallest band to the largest, and it holds within account: the 68 advertisers running both a 50,000+ audience and an under-15,000 one paid 24% less per send on the big one [−38%, −14%], cheaper in 56 of 68. The under-5,000 band is mostly retargeting pools — the dearest send and a competitive cost per lead, because warm people respond. For cold campaigns, widen the audience before you raise the bid.
Cost per send by audience type — it does not move
| Audience | Campaigns | Open rate | Lead rate | Cost per send | Cost per lead |
|---|---|---|---|---|---|
| Cold (attribute targeting) | 512 | 43.7% | 0.15% | $0.33 | $126 |
| Uploaded list | 372 | 38.1% | 0.11% | $0.61 | $340 |
| Retargeting | 206 | 47.6% | 0.14% | $0.47 | $213 |
Cross-panel the numbers differ, but paired within account the cost per send is the same: retargeting vs cold +6% (ns), list vs cold +21% (this one is significant — lists cost more to reach), conversation vs message ad −15% (ns), seniority filter +6% (ns). Cost per send is the bid you type and the size of the audience, not who is in it. What the audience changes is response: retargeting is 23% cheaper per lead than cold and 36% cheaper than a list, on a 71% higher lead rate. The audience chapter is here.
Cost by region: US, UK, Europe
| Region | Campaigns | Open rate | Lead rate | Cost per send | Cost per lead |
|---|---|---|---|---|---|
| US | 686 | 37.4% | 0.03% | $0.52 | $351 |
| UK | 81 | 42.8% | 0.14% | $0.63 | $188 |
| EU | 229 | 46.4% | 0.14% | $0.23 | $111 |
| Mixed or none | 592 | 43.5% | 0.10% | $0.40 | $158 |
The US inbox is the most contested: lowest open rate, lowest lead rate, three times the cost per lead of continental Europe. The UK pays the most per send ($0.63) but opens and converts well, so lands in the middle on cost per lead. In pounds, Kiin's UK operating range for a conversation ad lead is £50–£100 average and under £50 strong — the wider UK picture is in LinkedIn Ads cost UK.
Cost per lead: the full set of levers
Ten cheapest accounts against ten most expensive, from the study:
| Cheapest 10 | Most expensive 10 | |
|---|---|---|
| Cost per lead | $13 | $1,776 |
| Cost per send | $0.107 | $1.192 |
| Bid per send | $0.35 | $1.03 |
| Audience size | 97,000 | 17,000 |
| Cold share of spend | 98% | 26% |
| Uploaded list share | 0% | 31% |
| Lead form share | 100% | 95% |
Low bid, big audience, no uploaded list, lead gen form attached. The expensive accounts bid three times as much on audiences a fifth the size, mostly lists. The form matters because 41% of people who open a LinkedIn lead form submit it, against 5% who convert from a landing page click — which is also why message-ad leads come out 33% cheaper than single-image lead-form leads in the same account.
Budget: what a conversation ad campaign costs to run
At the median $0.42 per send and 0.09% lead rate, $1,000 buys about 2,400 sends, 1,000 opens and 2 leads. At the top-quartile settings ($0.23 per send, 0.22% lead rate) the same $1,000 buys 4,300 sends and 10 leads. The 30-day cap means a 20,000-person audience can absorb at most 20,000 sends a month — roughly $4,600–$8,400 at these prices — so budget beyond that goes nowhere without a bigger audience. Kiin's minimum for a cold conversation ad campaign is a 15,000-person audience; retargeting pools can be smaller because they respond. Where the format sits in a full budget is on the LinkedIn Ads management page.