The Quick History
If you're searching for "Sponsored InMail," here's what happened: LinkedIn renamed Sponsored InMail to Message Ads in 2020 and introduced Conversation Ads as a new, separate format in the same year. Both are inbox ad formats — they land in your prospect's LinkedIn messaging — but they work differently.
Most people still search for "Sponsored InMail" because that was the name for years. LinkedIn's API still labels the format SPONSORED_INMAIL. Both formats are alive, both sit at the bottom of a full-funnel LinkedIn Ads structure, and — this is the part we got wrong for years — neither is cheaper per lead than the other.
Single message, one CTA
Static message delivered to inbox. One call-to-action button. Prospect can either click or ignore. No branching, no multiple paths. Take it or leave it.
Interactive buttons, multiple paths
Message with 2–5 clickable buttons. Each button leads to a new message with more options. Branching conversation flow. Multiple conversion paths in one send.
Conversation Ads vs Message Ads: What the Data Says
Across the whole panel in Kiin Labs' 2026 conversation ads study — 1,588 campaigns, 263 accounts, $7.7M — message ads look three times cheaper per lead than conversation ads ($111 vs $347 at the campaign median). That number is misleading: 72% of the spend is on conversation ads, and the advertisers running them are the bigger, list-heavy, higher-bid accounts. So the study paired the two formats inside the 53 accounts running both.
| Conversation ad vs message ad, same account (n=53) | Ratio | 95% CI |
|---|---|---|
| Cost per lead | +36% | [−16%, +158%] — a tie |
| Open rate | −20% | [−25%, −14%] |
| Form completion | +21% | [+2%, +34%] |
| Cost per send | −15% | [−31%, +2%] (ns) |
Two effects are real and they cancel. Conversation ads get 20% fewer opens — the chat UI with buttons is a heavier thing to open than a plain message, and it lost in 43 of the 53 accounts. But the people who reach the form complete it 21% more often, because clicking through a button or two has qualified them. The price of a lead comes out the same. We used to tell clients conversation ads "win"; the paired data says they don't, and neither do message ads.
What conversation ads give you that message ads can't:
- Sorting. "Book a demo" / "Send me the case study" / "Not right now" lets one send serve three intents, and the button someone picks tells sales what they are before the call.
- Button data. You see which paths people take and where they drop, so you can cut branches that don't convert.
What message ads give you: a simpler message that more people open, and nothing to build. For a single offer to a warm audience, that is often all you need.
Where the buttons earn their keep: open with a $100 gift card offer for a 30-minute demo. Primary button "Book a demo" (calendar link). Secondary "Tell me more" (a two-line value prop, then the demo offer again). Tertiary "Not right now" (a case study or newsletter). In Kiin's accounts this flow produces SQLs from $59 on retargeting pools to $150–$400 cold.
When to Use Message Ads
Message ads are the simpler tool and open 20% more often. Use them when there is one thing to say and one thing to do:
- Event invitations. "We're hosting a webinar on [topic] next Thursday. Click to register." One action, no branching needed.
- Simple content distribution. "We just published our 2026 benchmarks report. Click to download." Single CTA, no alternatives.
- Quick announcements. Product launches, feature updates, or company news where you just need a click-through to a landing page.
For demand capture — demos, meetings, SQLs — use conversation ads when the offer needs sorting and message ads when it is one thing. Whichever you pick, the settings that actually move cost per lead are the same for both: the audience (retargeting gets 71% more leads per send than cold and beats uploaded lists by 36% per lead, same account), the bid (bid low — the highest-bid campaign pays 80% more per send for the same open rate) and the lead gen form (41% of form opens submit). All three are in the benchmarks report.
Setting Up Conversation Ads
Conversation Ads are created in LinkedIn Campaign Manager under the "Messaging" ad format. Key setup details:
- Sender: The message comes from a real person's LinkedIn profile — typically the founder, CEO, or head of sales. The sender must be a first-degree connection of the LinkedIn account connected to Campaign Manager, or an employee of the company page.
- Flow builder: Campaign Manager has a visual flow builder where you map out each message and its buttons. Keep the opening message short (2–3 sentences max). Lead with the offer, not the pitch.
- Buttons: 2–5 buttons per message. Use action-oriented labels: "Book my demo," "Show me results," "Tell me more." Avoid vague labels like "Learn more" or "Click here."
- Bidding: Bid low — LinkedIn's minimum, not its recommendation. In the same account the highest-bid campaign pays 80% more per send and 44% more per lead for the same open rate, and the median campaign pays 62% of its bid; why we reversed our bidding advice. Conversation Ads are charged per send, not per click.
The most common mistake is building a Conversation Ad flow with too many branches, too many messages, and too many options. Keep it simple: one opening message with 2–3 buttons, one follow-up message per path, and a clear conversion action at every endpoint. Three total messages maximum. Every additional step loses prospects. The goal is a booked meeting, not a conversation.