Why Attribution Really Matters For Product Listing Ads

With the holiday shopping season in full steam, advertisers are continuing to invest significantly in Google Shopping via Product Listing Ad (PLA) campaigns. Given the different format of these ads, one might expect users to interact differently than regular search ads.

Perhaps people interact with them earlier in the sales funnel because these ads have images. If so, do they assist regular search ads? Further, do they contribute substantially to a search marketers campaign in terms of both volume and ROI?

I analyzed several PLA campaigns and found that advertisers would do well to measure PLA campaign performance from a multi-click attribution lens. But first, how much are retail advertisers spending on PLA?

PLA Spend Is Currently 8% Of Google Spend For Retailers

An analysis of PLA spend for several dozen retailers reveals that the mean percentage of PLA spend, as a fraction of total Google spend is about 8.4%, the median being 7.1%. There were some retailers where PLAs represent over 30% of spend.

Thus, for any retailer PLAs can no longer be ignored and needs the same attention (perhaps more, owing to the complexity of the auction process) as a regular search campaign needs.

Multi-click Assist Funnels Play A Big Role For PLA Campaigns

Assisted paid search funnels are those funnels where the user starts with one search term but converts on another search term after 2 or more searches. When I looked at paid search assist funnels in the past, assisted funnels formed only 10% of all funnels. This is quite different for PLA campaigns.

The graph above shows, the percentage of conversions that were assisted when a PLA campaign was involved versus those that were not.

For all three advertisers the percentage of assisted funnels was substantially higher when a PLA campaign was part of the funnel. This begs the question – how much does last click attribution affect PLA performance measurement?

Last Click Attribution Typically Under-reports PLA Performance By 15%

When analyzing funnels containing PLA clicks for several advertisers I found that funnels that begin with a click on a PLA ad, end with a conversion on regular search ad about 15% of the time.

In other words, it means that last click attribution would miss about 15% of all PLA conversions.

Note that for some advertisers, such as Advertiser 3, the number is much higher.

Key Takeaways

1. Efficient management of PLA campaigns matters more than ever before. With over 8% of spend on Google going to PLA for retailers, it has become very important for search marketers to manage their PLA campaigns well. This not only includes feed management but also campaign and bid management.
2. PLA campaigns work earlier in the search funnel than regular search ads. Since about 1 in 4 PLA funnels are multi click funnels, consumers on average are clicking on PLA ads earlier in the conversion path as compared to regular search ads, where multi click funnels form only 10% of all paths.
3. Multi click attribution really matters for PLA. Since 15% (often more) funnels that begin with a PLA ad end with a non PLA ad, looking at PLA performance from a last click perspective will underreport its performance by the same amount. To get a true understanding of the performance of PLA campaigns advertisers really need to look at PLA campaign performance with a multi click attribution lens.