I've watched a marketing automation project fail.

It was a case study on how not to implement marketing automation.

Take, probably the best marketing automation system in the world, give it to a bunch a people that don't understand social media, marketing automation, give them 6 months and you get the most expensive email system.

All the classics mistakes were made, but it came down to two things.  The people on the project didn't have the right skills.  This meant it was treated as an IT project to replicate current processes rather than the transformation that the business wanted and expected.

After the initial launch, the business went back to doing it all manually and it was swept "under the carpet".