Here are some important reasons why you should choose Adwords conversion tracking over GA e-commerce tracking.
Here are the advantages
1. Remarketing audiences can be populated retrospectively. GA audience start from the day they are created so you have to wait for numbers to accrue. Low volume accounts may struggle to gain traction quickly unless you use the Adwords Tag.
2. The Adwords Tag allows you to see the path to conversion. You can see which keywords started the user journey, and which were the last converting keywords. This means, you can see the added value that your more generic keywords many have in generating returning brand visits. You can find this report in the Attribution section on the Tools tab.
3. ON a related note, the Adwords tag also allows you to see the number of assisted clicks in the main reporting interface – just make sure the column is switched on.
Disadvantages to using the Adwords Conversion Tag
1. You need to be aware of the date attribution. Adwords will log the conversion on the date of the last Adwords click. Therefore if the last click from Organic caused the conversion more than 30 days ago, your historic data could change. (see days to conversion report)
2. Adwords will attribute more conversions to Adwords than GA, causing larger data discrepancies. Be aware of the last click attribution model means different things to Adwords and GA. In Adwords, it means the last Adwords click, whereas in GA it means the last non-direct click. So Adwords will ignore an organic converting click and attribute it back to the last know Adwords click.
3. Native Adwords remarketing lists are based solely on page views. You can’t create the complexity of a GA audience segmentation. That’s why if you’re using GA audiences, make sure to create as many potentially useful lists as possible; basket abandoners and non-converters being the most basic and obvious.