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 gets a 71% higher lead rate than cold and is 36% cheaper per lead than a list; its cost per lead gap vs cold (−23%) is directional. 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.