Will there be any adverse effects on your website's SEO effectiveness and page ranking if you cross-link it to many of your other websites? Cross-linking, in many ways, seems like an artifact of the bygone era of Web 1.0 — wherein moving GIFs and hard-to-load flash intros were the norm, and in order for one of your sites to gain traffic, it was considered a good idea to link it to another, more popular site regardless of whether or not they're even tangentially related to each other.