Paid search marketing efforts have a big problem. It should come as no surprise that users of all those lovely Apple devices, like the iPhone, iPad and iPod Touch primarily use the Safari browser (let's not forget the Mac, as well). The Safari browser by default disables tracking cookies for online ads and other site visitor activities.

So for online marketeers, the good news is that your campaigns may be going well. The bad news is that as Apple iOS devices (not to mention the Mac) become more ubiquitous, your ability to track your success accurately is becoming increasingly impossible.

Marin Software, a paid search agency, recently published a white paper based on new research that shows 80% of all web clicks on Apple iOS devices are not getting counted by cookies. On the Mac, 50% of all clicks are going undetected by tracking cookies.

Keep in mind, there are now 130 million iOS devices in use out there. Marin Software claims that when you crunch these numbers with the numbers of other browsers operating with their cookies disabled (proactively by its users), it adds up to a staggering 38% of paid-search clicks not getting counted.

That's a lot of money left on the table.

So now what? For years, online advertising has grown year by year exponentially at times. I don't think this is going to kill the goose that laid the golden egg. But, it does appear to be significantly winged.

P.S. Don't expect a lot of sympathy from consumers on this one.