Question
I use UTM parameters to track all the links I use on different advertising channels (Adwords, FB ads, Bing ads, etc.).
However, since UTM parameters will cache when a user first comes to my website if that user initially came from a Facebook Ad, then left my site and came back through a Google Adwords Ad the UTM parameter will list Facebook Ad but the conversion actually happened with the Adwords ad.
So my question is how can I track if Facebook ads is actually helping/complementing my Adwords ads?
Answer
You should use all the tracking systems in Bing, Facebok, etc, so you know how much they are contributing to business.
On the other side, you can use Attribution (different models) and Assisted Conversions reporting on Analytics, so you can find out which channels are closing the sales and which ones are opening them.