@Wize, Actually, even the customer are going to be happy. Individual are probably smart enough to not buy the product of Dilbert's company. Leaving only private and public institution, going probably for the lowest bidder. If the product is crappy and the support is getting worse, chance are less business are going to buy the product, meaning less user. Less user mean less unhappy peoples and more potentially happy user :p
Your solution is clearly a win-win scenario for everyone.
@BritTim, yes, I have seen this technique being used. Simply stop talking with the offender and send all requests through the boss. The effect is subtle yet extremely annoying. Imagine the CEO coming to you politely and saying "Ted requested that you will forward him a copy of the document. Can you do it? When? Great, I will call Ted to tell him the good news".
This is annoying because the Boss will assume Ted has requested it and you refused. This it makes you look like a weasel who refuses to share information, and you can't refute this since the Boss will not ask you, assuming you might lie about that.