Aggregation and SEO

The only reason that some people do this is tracking outbound clicks. They still have a standard 301 redirect from the on-site link ot the off-site link, which passes the same “rank” as a direct link would.

You need to understand one very important concept here. “Link juice” doesn’t get diluted or sapped by sending visitors to another site. Google actually likes it when you link to other relevant pages, so let the links go through naturally.