Attribution Management definition

attribution management:

noun

(Online advertising) determining to what you can attribute the sale or close to; giving credit where credit's due;

e.g.: 'You'll need an attribution management software to really know how effective your budget is'

attribute

verb
Pronunciation:/əˈtrɪbjuːt/
(attribute something to)

regard something as being caused by

e.g.: 'he attributed the firm's success to the efforts of the managing director', 'his resignation was attributed to stress'

Derivation:
late 15th century: the noun from Old French attribut =  allotted, from the verb attribuere,
'to assign'

To further clarify: 
A business may use either SEO, AdWords, banner ads, affiliates, forum-posting, Social-Media, email, Facebook ads, Cost-per-View (pop-up) banners.
Although it would be possible to see which one of these channels converted, it would not be possible to determine which one of these was the deciding factor in closing the deal.
To find this out conclusively, one would need a software to determin, for example: which particular email was the best "introducer", which affiliate was the best influencer, or what type of ad-message leads to the highest profit (not necesarily to the highest conversions).

Also serves as the definition of 'attribution modelling'.

model

verb
devise a representation, especially a mathematical one , of (a phenomenon or system):
e.g.: 'a computer program that can model the behaviour of smoke'

Derivation:
late 16th century denoting a set of plans of a building