The blog spammers must be getting desperate. The only other explanation I can think of is courtesy (keeping offensive language out of the posts), and I just can’t ascribe that motive to them.
The latest attack on this site consists of randomly-generated alphanumeric strings. Name? ah87fdfbqpo3q9483fhc. Email? firstname.lastname@example.org. URL? augfagfwi7832hr732rh8732fcfiuh.example.com. (I assume they have a wildcard DNS set up for random subdomains.) Content? Try something like “ads78shafi7 uigiutgw87n srgn743fnufc42.” (I’m typing my own gibberish, just in case the plan is to search for particular strings and see which sites have actually posted.)
The “advantage” of this approach is that there is no content to filter. No references to pills, poker or porn, no common phrases, not even empty generic statements like “I really like you’re site” and “Your an idiot” with links tossed in. It’s just a bunch of meaningless letters and numbers and a link. After all, the link is all the spammer needs, to get that coveted PageRank.