Matt Marshall over at VentureBeat (formerly Silicon Beat) is taking some lumps for a recent guest-blog post that was extremely critical of the online part-planning site Evite, because the author, Auren Hoffman, is an investor in a competing site known as Socializr — a fact that isn’t disclosed until almost the end of the piece, in a kind of offhand way. My friend Paul Kedrosky has taken a shot at Matt, as have others.

As Paul notes, this is a risk that someone like Matt takes by letting others write pieces on a site like VentureBeat. Is Evite a glacially-slow site that could use a good update? Sure. But that’s not the point. The fact that Auren’s criticisms are all totally valid becomes irrelevant as soon as we discover that he is both an investor in a competitor and a friend of the founder.

Should Matt have run the piece from Auren at all? Plenty of commenters on his site seem to believe he shouldn’t have, although Matt says he believed it was a worthwhile commentary, and one he agrees with. I think it’s questionable, but if he is going to run that kind of thing I would recommend a disclaimer at the top, so that readers go into it knowing what they are getting. Andrew Fife has some thoughts here.