I am developing a huge web portal and development of it will take 1 year. But I would like start with a promotion strategy before we launch it. I was thinking to create 3 mini sites with articles to get some traffic from search engines. When the portal will be ready I will move the entire content of half pages and make 301 redirect of each page to the new pages on the main site. Do you think that is a good idea or is it risky?