In-store clinics stand to revolutionize retail--not to mention health care.

NEW YORK -- The opportunity afforded retailers by urgent care clinics may be extraordinary, as they have the potential to become a new dimension of service in the medical care universe--but they aren't risk free. From the present perspective, it's hard to fault the retailers who are racing to place clinics in stores, including Target, Meijer and supermarket operator Minyard's, each of which has made major moves recently.

Indeed, Target did a turnaround on clinics. It gave up on them after CVS purchased the service provider with which it was working. Recently, Target found a new partner, Medcor, and is back on track to open clinics in stores.

The Target history points out a competitive issue that already is cropping up: Drug chains are looking at retail …