"Hub" → "Center|Node|Hub". Wait, they want to skip brands and names, so "hub" is okay to replace.
I need to be careful with the structure here. Also, maintaining grammar is important. Sometimes replacing a word with a synonym might change the sentence structure. For example, "often of a more adult nature" could become "frequently of a more mature kind" or similar.
And so on for each part. Let me verify that all terms are covered and the synonyms are accurate. I might need to adjust some to ensure they make sense in the context. For example, "captured the attention of many" has synonyms that are appropriate. Also, check that the synonyms are in the correct order, as the user might prefer the first one to be as accurate as possible.
Next, the second paragraph. Key terms are "a particular type of online content", "significant following online".