lucy24 - 3:13 am on Jul 27, 2013 (gmt 0)
I see no reason to develop one.
Depends what kind of site you've got. If your website is an adjunct to a physical business you'd be nuts not to have something mobile-usable, because your potential customers are pulling out their cell phones to find out what hours you're open and whether you still have that special on anchovies.
If you've got a site that people settle into at the end of the day with their laptops, or while they're in front of the computer at work, then no loss.