Advertising, ethics and editorial freedom

In a recent blog post, Roopinder Tara included this throw-away comment: Pure bloggers don’t do advertising, so no worry about advertising pressure — the secret and unstated fear of us all in the trade press. I respect Roopinder, but this kind of “pure blogger” label irritates me. I have an ad on my blog for geeky T-shirts, so I’m an impure blogger? Somebody please explain the reasoning behind that distinction, because I don’t understand it. Even if I accepted (say) Autodesk advertising, the idea that it would have any influence on what I choose to write is ridiculous. Yet I …