How many cruises do/should you book a year?

I suppose the easy answer to that is: 'As many as I can!'
Which is really the point of todays blog. Which is it better to do do you think? Book one 6 star cruise a year? Or several 4/5 star cruises for a cheaper price? One luxury cruise? Or several 'normal' cruises?
It's a difficult question to answer because it's so subjective, it really does depend on the person/persons. But there are a few pointers that might help you make up your mind.