It seems like an ad could be much more profitable than the donation banner, because ads can be targeted, even with zero behavioral history. For example, if I'm visiting a page on the new Tron movie, show me ads for the Daft Punk album! Odds are I might buy it.
Also, all of the things you said about ads could be said about in-house donation banners.
* Manipulate your baser desires to get you to part with your money
* Tend to be animated... etc
* Could provide vectors for malicious...
They would lose credibility because there would be a conflict of interest. Advertisers would be able to manipulate Wikipedia by threatening to remove ads unless they received favorable coverage, or negative coverage were removed.
Yes, I'm sure that ads could be more profitable than a donation banner. This is why most websites have ads instead of donation banners. However, Wikipedia is not a for-profit enterprise. It is an educational non-profit. If it were a for-profit enterprise, people would trust it much less, not as many people would contribute to it since they'd wonder why they were donating time and effort to a for-profit enterprise, etc.
And none of those things you list are true of a donation banner. Donating to an educational non-profit is not a "baser desire." I have never seen an animated banner asking for donations on Wikipedia, nor anywhere else that I can think of off the top of my head. And donation banners are coming straight from Wikipedia, not a third party; if they wanted to send malicious code, they could do so directly. The point is that ad networks are notorious vectors to allow malicious code to be injected by third parties into other people's sites.
> If it were a for-profit enterprise, people would trust it much less
You'd be surprised to learn how many people have no idea wikipedia is non-profit. A lot have no idea that you can edit articles and just assume it's a regular encyclopedia written by paid people. I have witnessed people telling me this too many times, and yes, it's pretty depressing.
Whether advertisers would have that influence depends on the specifics of the implementation; I think Wikipedia has the smarts and culture to resist any attempt at advertiser (or donor) manipulation.
The decision to make money from advertising (or other services other than charitable donations) is independent of the decision to be a mission-oriented non-profit or a for-profit. A non-profit can still make most of its budget from selling considerations; see for example The Mozilla Foundation.
It seems like an ad could be much more profitable than the donation banner, because ads can be targeted, even with zero behavioral history. For example, if I'm visiting a page on the new Tron movie, show me ads for the Daft Punk album! Odds are I might buy it.
Also, all of the things you said about ads could be said about in-house donation banners.