Speaking generally here, advertising is not the same as spamming. Spamming implies some sort of high volume and distributing the spam widely to people who don't want it. Advertising is not disallowed and in fact is one of the use cases for SP (those wishing to promote their content can buy SP and use it to vote up their own posts).
On the other hand, if you don't like seeing someone's advertisements, you should unfollow them or mute them. If it is posted with inappropriate tags or otherwise attempts to unfairly gain visibility, then downvoting it is appropriate.
Hokay, got it! thanks for the comprehensive answer . I have no problem with the content, in fact I enjoy his posts..was just seeking clarity.