When stencils that advertise corporate, and sometimes small business, products get posted in this site, Stencil Archive will usually write "advert" into the title of the jpg file. When Stencil Archive started back in 2002, there were few websites that had non-commercial stencils compiled and shared. The many hits that appeared in Google were for industrial-made, crafting stencils. The kinds you buy in art stores.
There have been many guerilla marketing stencil campaigns over the years. IBM, the TV series "4400" and several other corporate blasts paid artists to make the images, got them cut by machines, and then usually paid crews to paint them. Some of these corporations paid fines to have the ads removed off of the sidewalks. I think the best campaign was by Adult Swin. They had people put up LED-lit graffiti to promote "Aqua Teen Hunger Force" (full disclosure: Stencil Archive thinks ATHF is hilarious), prompting concerned citizens to call authorities and decry terrorism. Some of these devices appeared in San Francisco, and they were gone within hours of going up - most likely stolen by fans willing to climb up poles to take them down.
Morgoan Spurlock, a sly critic of mainstream culture, has a new film out titled "[corporation name] Presents the Greatest Movie Ever Sold." Spurlock funded the whole documentary project by whoring himself out to anyone willing to have product placement in the film. It's a crafty film, with funny moments as well as telling moments about our culture's acceptance for advertising, marketing, and product placement.
Spurlock needed a guerilla marketing campaign, so he got a famous LA marketing designer to give him ideas, got Ron English to make a street poster to paste up, and got JRF to make a stencil for the movie. In the movie you see the stencil getting hand-cut and then painted, most likely on LA streets. I haven't seen the stencil up in San Francisco, but did find the PDF to download and cut DIY style. Making the stencil available is similar to activists sharing stencils, Shepard Fairey's giving away the Obey stencil image, etc.
The movie is worth watching. Painting the stencils is up to the individual! With this doc's slick marketing campaign, you'd think that I could give you a link to easily download the images. Turns out the film's flashy website won't easily share the link, so you'll have to go to the home page at look for "Download the Stencils" at the bottom (watch out for that pesky trailer pop up).