This user (among others) has been posting a lot of questions lately which contain nothing but spam. I'm not sure about the reason for the posts, but I would guess it has to do with search engine indexing. In that case, the longer the posts are active on math.SE, the more the user will profit from spamming.
I'm quite new here, so I might have misunderstood this, but I'm under the impression that the rules for deletion were changed quite recently, and nowadays posts that should be deleted are put on hold for a limited time before getting deleted.
If not available, I suggest that the moderators are equipped with the possibility to immediately remove obvious spam posts, such as the ones linked above. Apart from improving the signal-to-noise ratio in the question lists, it would also discourage spammers from using this site for their purposes (whatever they might be).
EDIT: Well, the linked user was banned while I was writing this. Users can obviously be banned, which causes all his/her questions to be deleted immediately. But what about individual questions? Isn't the [on hold] process unnecessary when it comes to very obvious spam posts?