Will other syndicated content hurt my serp?

*Sigh* I've seen you in other syndication threads already. Surely Alexa has told you about duplicate content by now? Did you read the links? Syndicated content is not duplicate content.

I think you're pretty close. If SEO for you begins and ends with backlinks and credit for them, you're right. Adding syndicated content won't help you.

On the other hand, adding carefully selected relevant content from others helps with relevance and authority. It also provides opportunities for strengthening your internal structure.

Tiny correction: If you post a republished article, Googlebot will see it. Google will index it. They just won't display it in most serps. Here's where relevance and authority come in, only this time they work in your favor.

One thing new syndicators often get stressed over is having their syndicated article outrank the original on their own site. Often the effect is temporary when the outranking site is something like an article directory. If the article is picked up by a site with more authority or relevance for a particular query, the syndicated copy may again outrank the original. In this case, the site with the syndicated copy could be yours.

For the author, this is still a good thing. Maybe not as good as someone finding the article on the author's site, but still good.