It looks like someone went through and flagged the now-deleted answers as spam, and a moderator responded to those flags by deleting the answers. I'm not sure why that person didn't flag the other answers as well.
Here is information from the May I Promote Here FAQ Section:
Be careful, because the community frowns on overt self-promotion and tends to vote it down and flag it as spam. Post good, relevant answers, and if some (but not all) happen to be about your product or website, so be it. However, you must disclose your affiliation in your answers.
If a huge percentage of your posts include a mention of your product or website, you're probably here for the wrong reasons.
(emphasis is mine)
Tip to Avoid Getting Flagged as Spam:
In short, the main thing your answer was really missing was "DISCLAIMER: I am affiliated with this product and am posting as per the faq." and if it were the only flag, someone may have edited in a disclaimer for you since your profile does mention who you are, and since you have a record of answering questions here. (In other words, you're obviously not here just to promote your product.)
If it helps, you don't lose any reputation from this as deleted answers don't count against the reputation score, and you had 0 upvotes before it was deleted.
What about the other deleted answers?
As for the other answers that were deleted, many of them were posted by users with 1 reputation, who hit our site and have never returned, and who didn't bother to read the FAQ. I think your answer just got caught up in the mix of flags on the other posts.
However, we won't be undeleting them. Instead, I believe the best course of action is simply to delete the question, since it brings us no value and just encourages spam.
In fact, most of the other non-deleted answers don't really bring us much value as a site to get expert answers to your questions.
See the next section for an understanding of why we close questions and what we're hoping to gain from our scope changes, and why I recommend blanket deletion. Thank you for bringing this question to meta!
I also notice now that the question is "closed" -- but it still seems to be "active" in a sense. (I don't completely understand the "closed" status, nor why this particular question was closed)
This question is a poll from our early days, about a month into our public beta. At the time, we were new and still trying to figure out the scope of our site. Recently, we've committed to improving the quality of PMSE so that we're better than what's out there on the Internet.
In this question, the asker is asking for a list of things, and this question isn't really a good fit for Stack Exchange. From Q&A is Hard, Let's Go Shopping:
...technology moves so rapidly that the best shopping recommendations will be utterly obsolete within a year! What’s the point of a bunch of labor intensive questions that provide only temporary benefit to a limited (some might say Too Localized) audience? There isn’t any. That’s what we concluded, and we explicitly disallowed shopping questions.
If such a question were asked today, we would close it immediately and work with the asker to improve the question so that we might reopen it as something that gets answers that will be relevant for years. Consider the two examples from the blog post:
Poll/Shopping Question: May be obsolete in a year:
Q: What’s the best low light point-and-shoot camera?
A: Canon S90 and Lumix LX3.
Better question: Provide skills to make good shopping decision. Answers valid for years to come:
Q: How do I tell which point-and-shoot cameras take good low light photos?
A: I strongly recommend looking for something with
- a fast lens (2.0 at least)
- reasonable ISO handling (at least 400, but preferably 800)
- the biggest sensor available
The sum of these factors are really critical for low light situations.
The second question is much more relevant to future visitors. The second type of question also shows us how to make a good decision about a product, and it also discourages spam answers.
For more information on closing questions, please see the FAQ Section on Closing Questions.