What is the purpose of acquisition program

Acquisition is the status that says "This Program is the first time this lead ever came into this system" So that program gets the "credit" for creating a  net new lead.

This is very important if you are using RCE or if you rely on the Program Analyzer or Program Performance reports.

Normally acquisition is set for a net new lead that comes in via a related form. But you can assign this during a list import. The acquisition only occurs for net new leads.

yes, you should assign this to imported lists like Trade Shows, etc.

I might change my answer depending on how you are using your external tools. For instance, when you import a list from Data.com, are you importing that for a general use, or for a specific email? Or do you assign Data.com leads to a "Data.com Acquisition Program"?

General use AND specific emails e.g. product registration submissions that have selected other newsletter types. We'd want to send them: check out updated product, as well as recall, thanks, etc.

Currently I import those lists in a user defined list e.g. "2014 Product Registrations", setting their lead source to "Product Registration".

Possibly I am seeing this incorrectly?

Acquisition Program & Lead Source can be the same or different. For my company I define them as 

Lead Source - The original place that a person came from where they learned about my company
Acquisition Program - The original piece of content/Marketing effort that got us a new lead's contact information.

I create a program for every list import. 

Want to know more? Check out our summit presentation > marketo.tv/summit2014/use-marketo-analytics-to-deliver-the-right-metrics/