This morning the active questions page is flooded with spammy-like answers from this user: satomisatomi.
They all suggest to use the same software, and they are all structured in the same way, starting with an excerpt like this one:
How about Astah? Very easy to use. There are paid version (Astah Professional) and free version (Astah Community).
Followed by an image illustrating a relevant feature of that software pertinent to the specific question.
Something similiar happens also in her answers on Stack Overflow, where the answers themselves look less spammy than those posted here, because the software is not always explicitly mentioned, but this is compensated by the fact that each image present in her answers (image present in almost any answer) comes with a watermark on the bottom-right corner reporting "powered by Astah".
Also, as it comes up from her profile page, she's part of the tech support for that tool:
Tech support of UML, SysML, Mind Mapping tool - Astah
Finally let's take a look at when the questions she answered were posted:
So indeed those questions were searched in order to be answered.
Now that software, as stated also in her answers, comes both in a free and in a paid version, and her answers (at least on Stack Overflow) basically also answer the question, so I wouldn't classify this as the classic blatant spamming, but this behavior looks indeed suspicious and looks like a subtler way to spam that software. Even giving the benefit of the doubt, is this whole thing acceptable?