I have made more than 100 blogs on blogger and wordpress.com in last 4-5 yrs.. The total number of pages indexed on google is above 100,000. But now I want to shift all my blogs to my own domain which is pretty new. What should I do so that I get all my old pages indexed even when I hav shifted them to a new domain? Should I just delete the old blogs, so that google doesn't see the new pages as duplicate content? Keeping each blog on a separate subdomain? will this help? Please guide..
I would import them to the new blog if you are using the Word press software for your blog. This can be done quite easy through the Admin panel. As far as indexing, the search engines should find them if you use pinging. I would also submit a site map to Google which will show all your posts. If any of the blogger or word press blogs have PR, you would lose that on the new blog. However, I would not keep the content on all those blogs if you move it to the new one.