The Flash-based interactive Silver Bullet train is scheduled for its first departure in mid-April, and is gaining attention in the online advertising world because it is geo-targeted and time zone sensitive.

It also illustrates a concept online marketers have been reluctant to embrace: branding through presence in the right places, the right times. The train runs through demographic depots like Maxim.com and ESPN.com, whistling at the 21-34 year-old men expected to be hanging out there at the end of the workday.

A message trails behind the caboose saying "Catch the 4:53 to Happy Hour," complete with a "Happy Hour Countdown" clock, and, as the designing agency Avenue A/Razorfish tells the New York Times, maps to nearby bars stocked with Coors Light.

“We’re creating content," Levi Patterson, account director at Avenue A/Razorfish, told the Times, "but we’re letting people stay on the site they’re on and not redirecting them to our home page. We’re not asking the consumers to come to us and leave where they already are.”

And while that’s creative use of technology and branding concepts, the campaign could potentially be a nuisance to readers, considering the train momentarily rolls across content on the screen.

It will be interesting to see how it turns out; it could be well-received or it could enter the annoying advertisement hall of fame, right up there with HeadOn‘s "apply directly to the forehead spots" and alarm clocks buzzing over your car radio speakers that make you want to change the channel immediately.

The train may toe the line between clever and annoying. Over at TechDirt, Joe’s not buying it:

It’s hard to believe this will have the desired effect. When people see the ads, they’re not going to think to themselves, "ooh, that makes me want to order Coors Light when I get to the bar"; they’re going to think, "how can I make that damn train go away?"