Chris Applegate has an hilarious post well worth a read–An excerpt on reasons why–

• Client calls it an “internet blog”.
• Client has a “hilarious” viral they want you to “seed”, which turns out to be their latest TV ad on YouTube
• Client wants something edgy “like that suicide bomber viral” – but first subject to clearance by their legal department.
• “I don’t see why we need to pay you so much when we could just email all these bloggers a press release.”
• Client admits to anonymously posting links to their site on a range of forums.
• Client insists that you anonymously post links to their site on a range of forums.

via suw charman