It’s been ages since I looked at this so some details might have changed but you will get the general idea and what terms to search for.
Google by default works on ‘last visit attribution’ where any conversion is attributed to the last referrer.
E.g. Person visits from Blog A, then sees a re-targeting ad (B) and clicks, then some time later does a Google search © (or your direct link) and converts then the conversion is attributed to the google search.
But most people want ‘first visit attribution’ - or to know that the customer first found you on Blog A.
(The real pro’s use complicated schemes where it weights the conversion value between all the visits prior to conversion - so Blog A gets some of the credit, as does the re-targeting ad etc.)
Read more on this at Google Analytics Help - Attribution modeling overview
There are all sorts of things that break this though :-
- Different visits via different devices
- Visits from HTTPS sites (as no referer info passed)
- Conversions 30 days or more after a visit (e.g. if a customer coverts 31 days after visiting from Blog A then even first visit attribution will ‘forget’ that Blog A was involved).