Why don't I? Because basically I'm ambivalent about this. These are guys who are trying to earn a living, and how else are they supposed to make contact with potential customers?
"Landerson" at least is honest enough to make it clear that he's looking for business, in contrast to F3008, who is the current other major spammer.
I suppose I go for a middle way by pointing out to people who may be new to the forum who they're dealing with. It's then up to them whether they try and contact him or not. For all I know, he may be a good guide - or not.
It's quite possible that he's operated under another ID in the past, but not necessarily so. These guys are all Malagasy native speakers, so they'll all make broadly the same mistakes in their English and structure their texts in the same entertaining way. They will also have learned their English in the same school system, which I know from a fair amount of direct experience all too often produces the kind of dire English that characterises "Landerson" and other spammers.
Reporting a spammer, by the way, doesn't always get the postings removed - Some time ago, I reported F3008, who pretends to be a tourist, has signed himself with several different names over the past couple of years, and who until recently used to post a "guide's" e-mail address which he'd earlier given as his own. His postings weren't taken down - perhaps the moderators have the same sort of sympathy with these guys that I do.