Can a down economy cause clients to be crowding your doors? I would say it can. But there are several prerequisites.
Opportunity: With the economy down things are definitely changing: gas is down, unemployment up, overhead being slashed. So things are adjusting and this brings with it opportunity. Watch for these new opportunities. At Landis Computer we are talking to companies we didn't in the past because they no can longer afford their fulltime, internal IT person because of the economy. The economy may not bring you this exact benefit but DON'T miss the oppertunity it brings you.
Trust: My opinion is that when there is a lot of uncertainty people start talking to those they trust more frequently. I know I've gotten my trusted CPA's opinion on more things this year and I'm guessing many of you did too. I've asked trusted business freinds their opinion more this year too. My guess is most people are. You may not be a CPA but--Is your company one that people talk to when they want someone they can trust?
Predictability: Along with trust there is another thing people are looking for. People look for this at all times but when they are surrounded with uncertainty I think they do even more: Predictablity. I remember when Landis Computer first started some service requests were responded to in an astounding 5 minutes! The only problem was some weren't responded too for 4 days. And I found out painfully and first hand that people HATE unpredictability. Good systems avoid unpredictability. A good book that pounds home the need for and benefit of good systems is "The E-myth Revisited" by Michael Gerber. A book I recommend for business owners.
I believe that these things can dramatically increase the odds of your companies' fortunes being up when the economy is down.