Google Lags in Indexing New Sites

The other day I launched a new website. It's another one of my niche sites; exploiting a particular narrow trend or topic. Here's the breakdown of activities over the course of the first few days.

1. Register domain
   Install Drupal
   Load commonly used Drupal modules and configure the backend of the site
   Create documentation around the project, strategy, monetization, etc.
2. Install a suitable theme and work on the look and feel of the site
   Create a logo and other promotional graphics
   Register the brand name on various services: Twitter, Facebook, Youtube, Flickr
   Add the site to Google Analytics, Google Webmaster Tools, Google's index submission service
   Submit the site's sitemap.xml file to Google, Bing, et al.
3. Develop the site navigation and main sections
   Generate a few initial blog posts
4. Contact and interview subject matter experts in the niche this site is dedicated to
   Begin social networking involvement (traffic spikes this day for the first time)
5. Comment on relevant blog posts on the web; link back to the site
   Write enough posts for the next week and schedule to auto-publish each day
   Further research the niche and document who the experts and influencers are

Where's the problem? Despite heavy Twitter traffic, comment linking, and submitting my site to Google, it didn't get indexed until 6 days later. The domain was registered on a Friday. On Saturday I submitted everything I could to Google. By Wednesday, the comment linking (inbound links from external sites) showed up in Google, but I had to search for my domain name to find them. It took until early Thursday for all the site's content to finally show up in Google.