I feel obligation to respond, as I did pass a comment in a recent sitar forum post, which may have come across as totally anti..
But frankly I feel that the poster there has not been excessive in posting 13 posts over the last 6 months or so, although, like the old story of nothing for ages then a host of No 11 buses all coming at once, he's posted too many at once, and sometimes just not thinking about relevance to the thread. Some of the posts have been responding to thread requests, and, although this shouldn't carry any weight, the poster is referring to a website which with a click takes you to his competitors. At least one post was reacting to westsea's promotion of his own website, and indeed the bamboo rudra veena thingy, so very understandable.
OK so it's not very sophisticated marketing, verging on advertising spam, but I think my verdict is to say, David, give him a shot over the bows and advise him this isn't the way you'd normally expect people to behave, but give the guy another chance.