In advertising, superlatives rarely mean what they are meant to. However, there are times when "truth in advertising" gets stretched beyond reasonable limits. Case in point: the introduction of "unlimited" mobile data service plans by network providers such as Rogers' new Unlimited On-Device Mobile Browsing Plan in Canada.

At first glance, the plan seems fairly straightforward: unlimited mobile data and Internet access for a mere extra $7 per month on top of your existing phone plan. However, when you look a little more closely, the "unlimited" deal turns out to be anything but unlimited. There is a limit of 2,500 sent text messages per month, and 1,000 picture or video messages, despite the fact that these too are "data" and should be unlimited. Of greater concern is the fact that the deal only applies to select phones and does not include Blackberries, Windows Mobile devices, laptops using PC cards for mobile data access, or unlocked devices such as Apple's iPhone. The latter is still officially unavailable in Canada, but many wondered if the revealing of this "unlimited" plan was a clue that Rogers was about to announce that they had secured exclusive access to sell the iPhone in the Great White North. This does not appear to be the case at the moment.

If you don't have an approved phone, each of which require a three-year contract, charges will accumulate at CAN$0.05 per kilobyte. Rogers does have data access plans for BlackBerry owners, but they top off at a paltry 1.5MB of data per month. Rogers calculates this to be a good deal by estimating web pages to average at a mere 4KB each, something far removed from reality.

Of course, unlimited plans that aren't actually unlimited are not unique to Canada. Most US service providers also put a bandwidth cap on their "unlimited" plans as well. And even for regular wired Internet access, most ISPs have hidden bandwidth caps. Rogers has even been found to inject content into web pages to inform users that they are about to hit the bandwidth cap. Suddenly "unlimited" starts to look very limited indeed.