Why You Must Bid Aggressively
LinkedIn conversation ads have a unique constraint: each LinkedIn member can only receive one conversation ad per 30 days — from any advertiser, not just yours. That means you're competing with every other advertiser targeting that same person for a single slot per month.
If you bid too low and lose the auction, your ad isn't delivered. It's not like a feed ad where you get fewer impressions — you get zero. That prospect won't see your message for another 30 days, and by then the window might be closed. You need to win the auction, and the way to win is to bid high.
How the Second-Price Auction Works
LinkedIn uses a second-price auction for conversation ads. Here's what that means in practice:
You bid $100. The next highest bidder bids $0.40. You win the auction and pay approximately $0.50 — just above the second-highest bid. Your $100 bid guarantees you win. The second-price mechanism means you don't actually pay $100. You pay market rate, which for most B2B audiences is $0.50 to $1.00 per send.
This is why bidding $5 or $100 makes almost no practical difference to your cost. Both amounts are high enough to win most auctions, and you'll pay the same $0.50–$1.00 either way. The only risk of bidding high is in extremely competitive audiences where the second-highest bid is also high — but even then, the cost per send rarely exceeds $2–3.
What to Set Your Bid To
- £5 / $5–$10 — works for most B2B audiences, wins the vast majority of auctions
- $50–$100 — guaranteed delivery, use when targeting high-value or competitive audiences (C-suite at enterprise companies, for example)
- LinkedIn's recommended bid — ignore it, it's often too low and results in poor delivery
We typically set bids at £5 or $10 and monitor delivery. If delivery is slow (meaning you're not winning enough auctions), bump the bid up. Most of the time, $5–$10 is more than enough to win.
Whether you bid $5 or $100, your actual cost per send will be roughly the same — $0.50 to $1.00. The bid is just a ceiling that guarantees you win. Think of it as "what's the maximum I'd pay to get my message in front of this person?" Since the actual cost is almost always well below any reasonable bid, the answer is: bid high and don't think about it.
Common Mistakes
Using automated bidding. For conversation ads, always set a manual bid. Automated bidding strategies (like maximum delivery) can underbid on conversation ads and result in low delivery volume. Manual control guarantees you win auctions.
Panicking at the bid amount. First-time advertisers see "$100 bid" and assume they'll pay $100 per message. They won't. The second-price auction protects you. Your actual costs will be a fraction of your bid. Look at cost per send in your reporting — that's what matters.
Not monitoring delivery. If your campaign is spending slowly, the most likely reason is you're losing auctions. Increase the bid. The cost per send won't change much, but your delivery volume will increase dramatically because you're winning more auctions.
If you lose the auction for a particular member, you have to wait 30 days for the next opportunity. In B2B, where your target audience is already small, every lost auction is a missed conversation with a potential buyer. Bid to win every time. The cost difference between a winning $5 bid and a winning $100 bid is negligible — but the difference between winning and losing is your entire pipeline.