Advertisers pay a premium for a silent ad, which is usually only a “brand name” advertising. Readers see a brand name, that is all; no message, no text, only the logo of a company. Online, the website of the advertiser is one click away; in print, it is a matter of recognition. (Text from the source above)
It is a real advertisement strategy. Hence, I'd consider it biddable. Maybe its niche, but I'd see it in the XXX range IMO