Last summer, nearly every client that I talked with who wanted a CMS would ask for Mambo. This was in spite of Drupal's obvious superiority in terms of code, flexibility, and power.
I was forced to conclude that Drupal's biggest weakness was the first impression it was making. I spent about 2 minutes looking at drupal.org, and Mambo's homepage, and the cause of Drupal's weak first impression was dead obvious:
