Losing market share will impact on profits in the medium and long term. Most, if not all companies look to increase on a never-ending scale.
The problem with losing market share is that you inevitably begin to lose kudos too. Where once you were down with teh kidz, you're sliding rapidly to be down with the grampies. Where once teh yoof were wanting an ianything, now they are wanting blackberry, htc, samsung, etc.