There are many attribution models out in the market and in the not too distant future, there will be many more but, you have to start somewhere, so let’s start with Google AdWords attribution options.
Last click: The last click gets all the credit for the conversion. This is the oldest and most common attribution model so chances are, if you have not changed your attribution settings this is what you are looking at when you review your performance data. If a customer clicks two of your ads, AdWords will credit the conversion to the second ad (and the associated keyword, campaign, etc.).
First click: The first click gets all the credit for the conversion. Something that the Adrac team tends to use more often than not. Not least because our conversion contribution platforms allow Adrac to monitor multiple interactions across multiple devices as part of the conversion journey. In first click attribution, if a customer clicks two of your ads, AdWords will credit the conversion to the first ad (and the associated keyword, campaign, etc.).
Linear: Credit for the conversion gets distributed equally to every single click the customer made before converting.
Time decay: Every click gets some credit, but the closer the click is in the journey to the final conversion, the more credit it gets. If a customer clicks today, and then again a week from today and converts that day, the click today will get some credit for the conversion but the click a week from now will get a lot more credit.
Position-based: If there are more than two clicks in the journey, the first and last clicks each receive 40% of the credit for the conversion and the intervening click(s) get the remaining 20%, spread out evenly.
Data-driven: Google looks at thousands of signals to distribute credit for the conversion based upon its algorithmic understanding of how important each click was to the final conversion. This method is only available for accounts with a lot of data. Google doesn’t specify how much data you need to have, but in our experience you need to have tens of thousands of clicks per month.