I think there becomes a point at which self-promotion becomes ok, providing that the magnitude of the self-promotion is commensurate with the contribution. I feel that the author met that in this case, and I did not feel spammed.
Edit: Judging by the other comments, it appears that the author may have edited the post already to be less spammy. In any case, the current version has a good balance.
Edit: Judging by the other comments, it appears that the author may have edited the post already to be less spammy. In any case, the current version has a good balance.