According to the Stack Exchange definition spam is something that is purely promotional without any other plus value. So as it stands, those posts don't really qualify as spam as they do answer (part of) the questions. Nevertheless hidden advertising is definitely frowned upon, as once again by doing so I'm implicitly following the SE rules:
Avoid overt self-promotion.
The community tends to vote down overt self-promotion and flag it as spam. Post good, relevant answers, and if some (but not all) happen to be about your product or website, that’s okay. However, you must disclose your affiliation in your answers.
So by applying the rules you should ask for the affiliation and wait. You can also downvote the post temporarily, and then remove the negative vote if the op renders the post compliant to the rules. If not the downvote remains as an indirect flag for low quality. This is what I usually do.
Having said this, I also consider another criteria, namely the reason for which the user joined the site. The case at hand is a perfect example of this: the user just registered and mass-posted 4 answers on the same topic, all aimed at advertising their product. This tells me that, whilst the user might not be a spammer in the technical SE sense, he registered with the sole intent of (somewhat legally as per SE rules) pushing their product and thus add no value to the community. Yes, I judge the intentionality of the posts. What I do then is that I flag it for moderator attention saying exactly this. Turns out that by doing so I'm implicitly following the SE rules:
Avoid overt self-promotion.
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For more information you can refer to the more comprehensive help page from TSE on how not to be a spammer.