A small-time publisher puts out a book that’s about Beverly Hills from 1930 to 2005. The publisher already put out a book about Beverly Hills’ founding and first few decades. So:

Nowhere on Earth are sequels and the success that fosters them more apparent than in Hollywood’s bejeweled bedroom, Beverly Hills. This continuation of the history begun in Arcadia Publishing’s …

Yes, Beverly Hills is evidence of sequels. You look about and say to yourself, “Sequels have been here.” 
All right, the success that fosters sequels is evident. I’ll grant that. But what an odd way of dragging success into the conversation. A hit film can have a sequel. Therefore, the copy treats “sequel” as a synonym for movie success. But it isn’t, so the writer then has to think of a way to mention “success” directly (“the success that fosters them”). And the whole time the writer knows he/she is being clever because the book is a sequel and “sequel” is a movie term.