I am in a dilemma about a certain situation that I face. I am working in a boutique analytical consulting firm which looks into mortgage delinquencies. As a favour I have also been helping one of my acquaintances in his business which is very different from the daytime work that I do. This acquaintances work is focused on developing solutions for a few focus industries. I have been helping him (for free) in terms of idea generation around his product. I have invested non-trivial amount of effort in this pursuit and feel that I should add this experience to my MBA essays etc.
However I do not have any proof for this except for the acquaintance vouching for my work.
Since I helped him for free I do not have any receipt or any monetary proof of helping him out. I am wondering if this will be an impediment in adding this experience to my application since the b-schools mention that they will be validating all what has been written through a third party vendor and I am not sure what sort of proofs will stand their test.
Will it work if I add my acquaintance as a one of my recommenders?
Also can I add it as part of my resume?
Please let me know your thoughts.