If you are getting consistent showings, the price cannot be too far off, yet if no one comes back for a second look or makes offers, there is a problem. Besides price, it could be your location, neighborhood (which of course you can do nothing about) - or your home. Is it clean and neat? Free of clutter? No "weird" decorating or paint?
If you answer "yes" to those questions, then my thought is that you just have bad luck. That can happen, just as good luck can. You then have two choices: just keep at it, hoping your luck will change. Or take it off the market for a while and then relist, coming on as a "new" home just on the market. The new ones seem to stir up interest by their very newness. And there are customers who look at days on the market and bypass those that have been on too long (I don't think MLS should make that figure available to the public).