I like when they have rewards systems in place, like buy one get one free, or buy so many get a free product, of course that does not really apply to a computer business, but what you suggested,rewarding them for their custom, sounds good to me.

Of course good service, politeness and a good job done, will always make me go back to that company.when a company goes that extra mile for me also makes me want to deal with them again.

Cost does come into it for me, so value for money as well.