It would depend what the post was - if it was a detailed and interesting post that was relevant in more than one thread then I wouldn't consider it so; but if it was some white noise nonsense or a link to a not very interesting page then I would see it as spam. For example, if someone posted a detailed and interesting analysis of Australia/Pakistan game and posted it in the Australia, Pakistan and Quarter Finals threads then I wouldn't consider it spam since its relevant to the topics of those threads and you shouldn't be forced to reword a post because you are posting it somewhere else; but if someone posted "nice", "good team" or "very good" in twenty threads at once (we had lots of this a month ago) then yes, it would be spam.
e: also haha I had forgotten that I had linked lowtax's death threat in here - its a must watch imo