Promotional items as a media channel

I read an article recently on Media Post about the cost effectiveness of using advertising specialties (promotional gifts) as a media channel. This site is registered users only, but you can view the original research at the Advertising Specialties Institute.
The article claims that on a cost per impression basis in the US, it is cheaper to use branded caps, pens and bags as an advertising medium than any of the mainstream media - TV, newspapers, magazines, etc. This is certainly interesting for anyone who works in media, especially during these difficult economic times when cost effectiveness is more important than ever.
When I read the full report I thought the methodology looked extremely flawed. For example, in working out the cost per impression for a cap, the total impressions are worked out as: worn 6 times per month, for on average 7.1 months and each time it is worn, an average of 79 people come into contact with it = 3360 inpressions for a single cap. Using claimed recall for complex analysis like "on average how many people do you come into contact with each time you wear a cap" is going to have a huge error margin. I find it hard to believe that the average promotional cap is seen by 80 people every time it is worn or that they are worn on average 45 times - I've received dozens of these over the last 10 years and they are generally worn at an event and then thrown away or into the back of cupboard (there's my reliable sample size of one).
Furthermore, the comparison of a single brand logo with a full commercial, especially audio-visual is very difficult as the impressions certainly aren't equal in terms of how powerful they are to evoke shift in behaviour.
The study does have some interesting questions regarding favor towards the companies providing promotional items which probably not surprisingly, is generally very positive.

Despite its flawed methodology, the report is still worth a read if you work in marketing and I'm sure that for the right brands with the right objectives, promotional items could work a treat.