November 3, 2020
PPC Ad Extension Best Practices
By now, Google’s Target Impression Share bidding has been available for a little under two years. If you are considering trying it out, read on for a few advanced considerations you should make before testing. For more details on the bid strategy itself and how to set it up, check out this blog post first.
When you are making the decision to enable target impression share bidding on a given campaign, it is important to determine how you are going to evaluate its performance. As performance marketers, we are inclined to look at the algorithm’s effect on lead and revenue volume when testing a new strategy. However, this might not be the most effective way of gauging target impression share’s ability to perform, especially if your end goal is to meet an exposure or awareness objective.
Target impression share bidding will only use the placement option, percent impression share target, and max CPC limit that you specify in order to determine when and where your ad shows up. With this in mind, a more productive way to evaluate the bid strategy’s success would be to look at the following KPIs:
Because the above KPIs all pertain directly to the bid strategy’s target inputs, they are going to most accurately reflect its effectiveness. If you are concerned about performance KPIs that are not listed above, you might want to consider testing one of Google’s other automated bidding strategies that more closely align with your campaign’s goals, such as max conversions, max conversion value, target ROAS, or target CPA bidding.
Something else you should consider is the potential impact target impression share may have on your device performance. Although the extent of this difference can vary greatly depending on industry, current bidding strategy, ad copy, and other factors, in general we tend to see lower CPCs associated with mobile devices compared to desktop.
Below is an example of a client’s desktop and mobile CPCs before and after enabling target impression share bidding:
Although both desktop and mobile CPCs increased after enabling the bidding strategy, mobile CPCs were still nearly half of those observed on desktop. Alone, these metrics might not carry much meaning, but when you look at the trend in desktop and mobile spend during the same time, larger implications emerge:
Despite the period-over-period increase in desktop CPCs outpacing the growth in mobile CPCs, growth in mobile spend far outpaced that of desktop. Because target impression share bidding will simply optimize toward a campaign-level impression share target, it will often leverage the lower CPCs observed on mobile devices and re-route investment to mobile users in order to reach its overall impression share goal. If your goal is to set a campaign-level target impression share test, then you may inadvertently cause your campaign to invest more heavily toward users searching on mobile devices. For this reason, it is important to consider your current mobile device performance compared to desktop performance before implementing the bid strategy.
When enabling target impression share bidding, one other consideration you will need to make is which placement option to choose. Currently there are three available options:
Which placement option you select will largely depend on what the goal of your campaign is. More often than not you will be utilizing this bidding strategy to work towards some exposure or awareness goal, but depending on what keywords you are bidding on, what ad copy variations you are testing, or what your competition looks like, you might want to adjust your settings accordingly.
If you’re not sure where to start with target impression share, we recommend testing out this strategy on your branded search campaigns first, and then expanding out to your top non-brand keywords. For more help on Google Ads smart bidding testing, contact our team.