You wouldn’t want to accidentally smear makeup on your iPad (or iPhone, or iPod Touch) — but you might if it came in the form of an interactive ad.  Shortly after Lancome and Maybelline launched iPhone ads that sought to engage mobile viewers, L’Oreal Paris is now debuting its own interactive advertising for the iPhone and iPad.

Specifically, the app helps you find the right shade of (L’Oreal Paris) lipstick by asking questions about your hair- and skin-color

All three brands have created their apps on Apple’s new iAd platform. Maybelline is reporting that people spent a lot of time on their app (which helps you find your correct makeup shades) — an impressive 1 minute and 8 seconds, on average. While we’re not quite ready to call this the demise of the beauty counter lady,  this mobile Q&A-style advertising certainly beats looking for help in a deserted drugstore aisle.

What do you think?  If an ad popped up to ask you about a shade of lipstick, would you respond to it?