A new theory has been experimented. Indexing the URLs of all the pages on your website is important for SERP. The more pages you have under your domain that spiders can grab relevant content from, the better off your site is in search results. This is why SEO consultants and companies will always suggest that you create an XML sitemap for your website.
But what if your client can’t give you access to create a sitemap (we’ve seen this happen when a company website is part of a corporate system or franchise structure). What you can do, is try this new theory on how to index pages using Twitter to post your URLs.
Now, you don’t want to spam your followers with a whole bunch of links, but if it is relevant to what your posting, don’t miss out on the opportunity!
Here is a very intelligent article that walks you through an experiment with indexing pages through Twitter.