I guess I have a different definition, or at least a different threshold, for what I consider spam. This particular situation was not extreme but I still consider it spam. They continued emailing me around twice per month with the same offer despite me having been perfectly clear on at least two occasions that I was not interested. They did this for 14 months before giving up. I received another message at the 2 year mark that was an actual release announcement, which I do not consider spam.

Likely referring to the rate/ratio of contact/response from the commenter you're replying to.