Philips did not promote CD-i alone, it had several partners and retailers helping to market the CD-i brand. Salesmen travelling around showcasing the possibilities of CD-i were official CD-i partners, stickers like this confirmed the importance of it. Of course there's a lot we have never heard about: What did it take to become an official CD-i partner? Did you have to sign a contract, did you need to invest in it, did you just get a roll of stickers to protect your CD-i equipment? Were you paid to be a CD-i partner, or were you allowed to keep a percentage of the sales? I think this partnership is typically something that was used in USA - At least here in The Netherlands I was not aware of it, most marketing was done by Philips themselves, it was still a large company back then. But in the large countries in USA, it was more difficult for Philips to reach everyone, so it was more logic to work with partners to get the CD-i brand name better known.
[Credits: these pictures are courtesy of Retrostuff]