vCPM bidding can boost your campaign metrics – but is it at a cost to your visibility, TACoS and long-term growth?
There’s no doubt that lower ACOS and higher reach look good in your reporting, but dig a little deeper?
It can quickly become clear that those wins have come at a cost, especially across your Sponsored Display ads.
This is because, while vCPM prioritises impressions and visibility, it often does so at the expense of actual conversions.
And over time, that trade-off can start to hurt the most important performance driver of all – your organic ranking.
We asked our award-winning Amazon Ads experts to break it down for us…
Under the surface of vCPM
Advertisers often see improved ACOS under vCPM bidding – but that’s because it’s calculated on estimated conversions divided by spend, rather than on actual click-throughs.
So yes, the numbers may look better, but it’s possible that they’re masking a very different story in the background, with:
- TACoS increasing over time as organic contribution shrinks.
- Organic rank declining as conversion velocity slows.
- Profitability weakening, as more budget gets poured into unprofitable views rather than high-intent clicks.
Worse, if you’ve not got an eye on the bigger picture, this is the kind of shift that can creep in unnoticed – at least until your growth starts stalling and your costs start climbing.
The upside of vCPM
It’s not all bad news though, and vCPM bidding definitely does have its place, especially for:
- Awareness campaigns, where the goal is top-of-funnel visibility.
- Product launches, when you’re trying to reach broad audiences quickly.
- And retargeting, where impressions can keep your brand top-of-mind with warm shoppers.
The key is to choose vCPM for the right reasons. It’s not something you can lean on if your core KPIs are profitability and organic growth, for example.
And, like all things Amazon Ads, it’s not a set-and-forget approach. Getting the best from vCPM needs you to be on top of monitoring the most accurate of your data, and making sure it’s delivering the results you want.
Our Experts’ 4 tips for best vCPM practice
- Review your campaign objectives before implementing vCPM. If you’re chasing conversions or efficiency, CPC bidding is usually the better choice.
- Don’t optimise for the wrong metric or vanity figures – a lower ACOS under vCPM doesn’t always mean stronger performance.
- Monitor your TACoS and organic rank closely, because they’ll tell you the real story.
- And use vCPM strategically, deploying it for brand awareness or retargeting campaigns, not as a default setting.
The Bottom Line
vCPM bidding isn’t bad, it’s just often misunderstood.
Used in the right context, it can be great for supporting top-of-funnel growth and brand visibility.
But for performance campaigns? Be careful – it has the potential to quietly undermine your organic rank, inflate your TACoS and even hurt your long-term profitability.
Need help reviewing your ad bidding strategy? Our Amazon Ads experts can take a look under the hood, apply plenty of commercial clarity and regiour and help you refocus spend where it matters most.