I would say, not.
I had my own little experience with plagiarism when a Belgian craft company ripped off one of my knitting photos from Flickr to use in their product catalogue. Something I never would have spotted if an eagle eyed Flickr viewer hadn't spotted the picture, thought it looked familiar, tracked it down to my profile, and even scanned a copy of the brochure and then sent it to me as proof. I've got to tell you, I didn't feel flattered, I felt really pissed off.
When I used to be involved in historical re-enactment I wrote a series of articles for our local group's 'zine about hat making and garment construction, only to find out through a reader that another group was photocopying them right out of the 'zine, cutting and then pasting them into their own 'zine, without ever having had the courtesy to ask. I would have sent them originals to use if they had only asked, instead I got bent out of shape and told them to stop.
There must be many, many instances where creative people have their images and ideas ripped off. However, ripping them off for advertising or products just increases the likelihood that someone, somewhere along the line is going to spot it. So I find the blatant plagiarism documented on this blog post and this website astounding. Thankfully there are plenty of someones out there doing the spotting.