1. Unlike many other commercially successful bands like Elton John or Pink Floyd, their debut albums sold millions.
2. Their ambition of world conquest necessitated the contracting of a branded commercial airliner for their rigorous world touring.
5. Neither started off with a geographic focus in America, both started off releasing touring exclusively in Europe.
7. They both had an album oriented approach to producing their albums with each individual track sharing a similar musical theme with the other songs on the album.
8. They embraced and expressed their individualism
9. The trajectory of both their sales figures is very similar.
It took two and a half years between the release of their first studio album until they released their best selling album. From there, sales for both bands tapered off over a period of 10 years.