MMP is designed to provide performance metrics – “including attribution, lifetime value, downstream conversions, ROI, etc” – to mobile app developers who advertise their apps on Facebook.

Kontagent and HasOffers were taken out of the programme after the violations were uncovered during an audit process.

Kontagent’s CEO Andy Yang has written a lengthy blog post outlining what went wrong.

The first issue, he said, was that Kontagent had stored MMP data longer than Facebook’s policy allowed for, even though it was encrypted – which “was not required by Facebook”, said Yang. 

Kontagent also failed to store data collected via MMP separately from all other data collected, although it did store the data encryption keys separately. Lastly, Facebook’s audit revealed that the firm did not display the MMP’s disclosure requirements in a prominent location in marketing materials.

“In short, Kontagent created an encryption policy that we designed to completely protect user privacy while addressing Facebook’s policy in one elegant solution,” said Yang. “In hindsight, while our intentions were good, we overthought the solution when a more basic approach would have better met Facebook’s requirements.

“I completely respect the audits that Facebook conducts to ensure their partners are properly compliant. We feel each of these requirements can be quickly addressed and we hope to have to the opportunity to participate in MMP again.”

Yang stressed that the rest of Kontagent’s relationship with Facebook “remains intact”.

“We will continue working with Facebook as a market-leading provider of analytics for their social and mobile app developers as well as for attribution on the web.”

HasOffers also published a blog by CEO Peter Hamilton, responding to the situation. “I want to be clear that we did not violate any privacy regulations, and there was no data leakage or inappropriate data provided to advertisers,” said Hamilton.

“We first disclosed all of our data storage and deletion processes with Facebook during an audit in September. We sought clarification on certain issues and offered solutions to allow our products to work within Facebook’s terms. We believed we were working collaboratively with Facebook to comply with their requests. Regardless of their recent and sudden decision, we remain hopeful and open to working with Facebook in the future.”

• Update 14/02/14: Added in comment from HasOffers, and link to blog post.