No, I think it would be ok to have advertizers sponsor pages. Here is an expansion on the idea. The ad is in small text and simply says:this page sponsored by [[Toyota]]. with a link to their *wikipedia* article. If one doesn't exist, they can write one, but it still must be NPOV. This type of low-impact advertizing often has (ironically) the biggest effect because people aren't as annoyed. A wikipedian could also sponsor the page with a link to their userpage. More than one person or company could sponsor a page. The homepage couldn't be sponsored. Each sponsor request would be screened to prevent linking [[Toyota|Toyota, the beat car company in the world]]. I would cost, say, $1 for 100 impressions, to encourage low-budget advertizers and users to sponsor things. I don't think this would lower our academic credibility at all.