This is just an example but let's say I own the domain: stocks.com. I'm targeting the keyword "stocks" so I backlink that domain Now I have pages on stocks.com that are stocks.com/penny-stocks and I'm targeting the keyword "penny stocks" as well. Another page I have stocks.com/stock-trading and I'm targeting the keyword "stock trading". Do I have to backlink ALL 3 url's stocks.com, stocks.com/penny-stocks, and stocks.com/stock-trading in order to rank in the keywords or do I just have to backlink the main domain stocks.com which then links to those other pages. Please clarify. Thanks.