jscs's comment that "Another way to make this point is that for total junk like this the affiliation part is completely irrelevant, and therefore disclosure doesn't even enter into it." is spot-on here when you consider what it actually means to disclose.
Consider the following post as an answer requesting suggestions on a software library:
Bes,t mal3 enl5rgement C5nadi5n ph5rmac:y ch333p |/14gr4; Ord3r today free shipppping best e.n.l.a.r.g.3.
What would constitute disclosure for the above post? I think it is obvious that adding a "disclosure" such as "I am affiliated with this ph5rmac:y" adds no additional information to the post that wasn't already obvious. No reasonable poster would post an advertisement like this if they were not affiliated with the vendor, so the very fact of posting is itself testimony to the poster's affiliation. Requiring that such unsolicited advertisements disclose affiliation has no practical meaning and is therefore inapplicable.
Noe consider an answer like:
I recommend the QuantumRPS library. It has all the applicable gizmos and also supports Web 2.0 throughput across socketspace and integration with COBOL 15 service jobs at Level 3.
Is the poster of the above answer affiliated? Maybe they are, maybe they aren't. Here is where disclosure matters, and why we require it for potentially plausible answers.
So, if a post can plausibly function as an otherwise on-topic and acceptable post, it requires affiliation disclosure if the poster is affiliated with a product or service promoted in the post. If a post is literally nothing more than an unsolicited ad, it's spam regardless of how many "disclosures" or "disclaimers" it has.
In other words, lack of disclosure is only a required element of spam if adding disclosure would change the character of the post and make it acceptable. If no amount of disclosure or additional disclosure will make the post suitable, it's already spam.