Do you like Marmite?
The theory goes that you either love the dark stuff or loathe it. It's hard to be indifferent to Marmite. In fact go to their web site and you are asked whether you like or loathe it
Now I love Marmite so much so that when they bring out a Special Marston's Pedigree Edition for the Ashes, of course I buy it. Cricket, beer and Marmite...bloke heaven!
So how do you service the people who really like your stuff?
What else do they like? Offer them a special. They will love you for it.
What's your special?