I bought a brand-new, previously unused (according to searches and archive.org) .com domain a month or two ago. I put up a simple placeholder for the planned website. Google "noticed" the new domain, and within a couple of days, the domain was in the index.

A week ago, the first vestiges of the site were put online. The site is unfinished, and so there are only about a dozen pages. I placed AdSense on some pages to test the style, and I added Google Analytics to the template. There is no XML sitemap and nothing was submitted to Google. Within two days, all the pages were indexed.

Ranking's not great, for the very obvious reason that there has been no promotion whatsoever and there are zero inbound links. But I think it shows a couple of things:

1. Now that Google is a registrar, it appears to visit all newly registered .com domains (from experience, this doesn't happen for ccTLDs, and Google isn't a registrar for those).

2. The AdSense bot and/or the Analytics service are feeding data back into the main index.

Are my assumptions true? What "non-traditional" methods (meaning other than by a visit from Googlebot following a link) are Google now using to discover and index new websites? How can we take advantage of these methods?