Do you know customers that have been in the same job since time began? Or that have the same lunch every day? Or lived in the same house for decades? In sales psychology terms we call them 'sameness' people. They simply don't like change, certainly not in the contexts mentioned.
Then again you may know customers who revel in change -- at work, possibly at home, again it can depend on the context. We call these 'difference' people. There is no right or wrong -- but if you can identify these particular characteristics in your customers, increasing sales is easy!
How about you?