Tie two filters together by time - Lead Creation and Add to List.

[Anonymous]

I use the web service API source type to create leads from OptinMonster, and those leads are then immediately added to a static list. Is there a way I can filter to see which leads originated from that api?
"person was created by web service api within a minute of being added to this list", indicating that api is the acquisition source.
I'd like to do a batch run to see who in my program meets this criteria.

[SanfordWhiteman]

The source should add a field to the leads also indicating the Lead Source.

[Anonymous]

I have seen this data populated in "Original Source Type" with Web Service API for my leads that are created in that way. 

However I second Sanford that you should be passing some other source data to help determine how the lead got to your site and what offer they responsed to.