Over the past couple of months we’ve been testing Google’s flexible bid strategy ‘eCPC’ – or ‘Enhanced CPC’ – with our clients to discover which strategy works best for which kind of account and in which circumstances. This method allows Google to increase your bid by up to 30% or decrease it by up to 100% in each auction depending on the likeliness of a conversion. Factors that are taken into consideration are real-time details such as browser, location, device and time of day. By activating the eCPC Google claims that you can achieve more conversions at a similar or even better CPO.
The test was run across several accounts from different customers and several markets in both Search and Shopping campaigns. Each test campaign was duplicated twice while the original one was paused so that performance wouldn’t be influenced by history. To avoid cannibalisation the campaigns ran on an alternating 2-hour schedule.
As Google needs performance information in order for the eCPC to work, we chose campaigns that had at least 100 conversions per month and let the test run for several months in order to allow for a four week period of data collection.
For the last weeks of the testing period we uploaded some standard RLSA lists but without bid modifiers to some of the campaigns as we wanted to find out if Google bases the anticipation of a conversion partly on information that’s provided by remarketing audiences.
eCPC Shows no Noticeably Positive Effect on Shopping Campaigns
In Shopping the eCPC campaigns did not perform better than the non-eCPC campaigns:
While the overall differences were very small, there is a tendency for CPCs, CR, and number of Conversions to be higher in eCPC campaigns. However, the higher CPCs outweigh the higher CR so that the effect on the CPO is negative.
Search Keeps What Google Promises
In our Search campaigns on the other hand we could see performance develop as promised:
CPCs were only 1% higher in the eCPC campaigns but CR was more than 7% higher, leading to a better CPO.
While our Shopping campaigns showed a similar amount of traffic our Search eCPC campaigns could achieve more clicks even though the number of Impressions was lower. This was due to a noticeably higher CTR.
The combination of more clicks and a better CR indeed lead to 10% more Conversions than in the non-eCPC campaigns as google promises.
Traffic is Shifted Towards RLSA
The RLSA test shows pretty interesting results:
While the amount of traffic coming in via RLSA lists is only 1% higher in our eCPC campaigns than in our non-eCPC campaigns, there is quite a big difference in CPCs.
As mentioned above we did not push our RLSA lists via bid modifiers and while the CPCs in the non-eCPC campaigns are almost identical, the eCPC campaigns show quite a variance. CPCs of clicks generated via RLSA lists are 10% higher than the CPCs of non-audience clicks. This shows that google does indeed shift traffic towards audiences as here the probability of a conversion is higher.
The eCPC is a Great Concept but Google Still Has Some Work to Do
Overall the variance in performance between eCPC and non-eCPC campaigns was not as significant as we had hoped for. However, activating the eCPC in Search can give your campaigns an additional push towards efficiency and additional conversions that could increase the amount of new customers for your shop. In Shopping however, the difference between eCPC and non-eCPC campaigns was not big enough to draw any conclusions. It does not seem to have a big influence on performance neither in a positive nor a negative way.
The RLSA results showed us that Google tries to work with users they already know which is a great concept but still needs some work to be done in order to work significantly better than the standard campaigns, especially in Shopping.