Is your product or service a 'must have'? A 'must have' is something your customers won't give up - even in a tough market.
Do you create outragous loyalty to your product - for example, a customer would pass a competing store to get to you? Or your service stays in the budget even when other things are cut?
On the low cost end, can you improve your experience so customers think - "I can't get through my day without my [X]!"
On the higher end, how safe is your product or service against the downturn? From a B2B market - when the boss comes down and tells the team to cut 10% of expenses...are you in that 'easy to cut' category? When I managed advertising for a large consumer goods company, it was easy to cut 10% from print advertising - an advertisement here, another in a different journal, cut a tradeshow - bingo, my 10%. But there were always some accounts, shows, journals I hated to cut. They were my 'must haves'.