Is it just me or is Adidas conveniently the kit maker for the 5 teams in question?
Liverpool
Real Madrid
AC Milan
Ajax
Bayern Munich
Maybe Adidas only sponsor the biggest and best teams.

Liverpool - most successful team in England
Madrid - most successful team in Spain
Munich - Most successful team in Germany
Ajax - Most successful team in Holland
AC Milan - Most successful team in Italy if the refs weren't corrupt
I'm sure it's obviously got something to do with Adidas being the kit sponsors but seems a nice touch to produce a boot for the hardest club to get into.