Here's what Eric Mugnier, Senior VP at M&C Saatchi Mobile has to say:
"The tablet is a mobile device. From a media-buying perspective, it’s a mobile device. It has app stores and all the specifics of a mobile platform.
"But it’s not a question whether you need to have a split between tablets and smartphones. The prices will be different, the ad units will be different, and the way you engage with the user. You need to make sure you approach that platform differently in the same way you would approach an iOS versus Android buy."
Translation: There is a difference.