Topic's recommendations are based on the content of the top-ranking pages for a given keyword. Its algorithm works best when analyzing informational content that is similar to what the publisher intends to produce or optimize.
However, there are some sites that hamper the algorithm because they are not representative of a publisher's content. These sites are excluded from any content briefs that are being created.
For example, Topic ignores wikipedia.org pages because they are extremely long and would include too many Topics to Cover. Topic also ignores some ecommerce sites as they would cause our system to recommend extraneous Topics.