As a big Netflix (NASDAQ:NFLX) fan, there are a lot of things I absolutely love about the service. However, I'm getting downright frustrated by one promise Netflix just isn't keeping for certain customers.

One of my regular Foolish correspondents, Peter, recently reminded me that Netflix's new Instant Watching feature is still available only for Windows PCs. That leaves users of Apple's (NASDAQ:AAPL) Mac OS or open-source Linux out in the cold. Folks who prefer alternative browsers like Firefox are out of luck, too, since Netflix requires Internet Explorer or nothing.

Sure, Microsoft (NASDAQ:MSFT) still commands a majority of the browser market, but it's become somewhat socially inept to play favorites like that in today's sophisticated tech world. A decade ago, Mac users might have resigned themselves to the sidelines, but their platform of choice has been gaining market share for the past few years. I can now use my Mac to stream video clips on Google's (NASDAQ:GOOG) YouTube or download video through iTunes to my heart's content. It's become rare, if no less unpleasant, for Mac users to feel locked out from services like Netflix's.

So what's your damage, Netflix? Since Instant Watching launched, Netflix has added new features, like "drag and drop" capability. Rubbing salt in the wound, Netflix announced in August that it had hit 10 million views since it launched the service in January. (That number had also allegedly doubled since July, although long-time Fool Rick Munarriz found the reality behind that press release pretty paltry.) Needless to say, I wasn't among those precious few taking advantage of instant gratification.

Worse yet, Netflix demonstrated a version of Watch Now for the Mac months ago. The technology needed to power it, Microsoft's Silverlight, recently made its public Mac debut. Yet Netflix still keeps Mac fans out of its online screenings.

Netflix has risen to fame on the strength of its innovative, customer-centric service. But its implementation of Instant Watching seems to suggest that some customers just aren't as important as others. I can bet that at least some Mac-using customers suspect that Netflix's profit motive is getting in the way of their happiness. Guess what, Netflix -- it's a huge strategic mistake to make any customers feel like they're low priority, and you're one of those companies that should know better.

Netflix is a Motley Fool Stock Advisor recommendation. Microsoft is a Motley Fool Inside Value selection. Try any of our Foolish newsletters free for 30 days.

Alyce Lomax does not own shares of any of the companies mentioned. The Fool's disclosure policy is platform-agnostic.