Progress with SEO project

I have been adding more content and getting some good feedback in terms of visitors (Google Analytics) and impressions (Google Adsense). What is really encouraging is that I am getting good bounce rate. Bounce rate indicates when your visitor has seen your content, realised it is not what they want and bounced out again - this is indicated on Google Analytics as a bounce rate of 100%. It is not an uncommon indicator, demonstrating that although you got the click to your site, they didn't hang around - your marketing may be working but your content doesn't live up to it.
The bounce rate for my new project is more like 25%, Google analytics also tells me that on average they hang around for 3 or 4 minutes and read 3 or 4 pages. What this tells me is that I am getting visitors and they are staying to read my content, which spurs me on to provide even more comprehensive content with the intention of trying to get the visitor to bookmark and revisit my site at a later date.
I have strategically placed some 'about' information that tells my visitors that more content is planned for the future. I have been sending out the odd link request and had a bit of a 'snotty' answer from one potential link site recently. He offered a critique of the site and pointed out where the site did not fulfill what he thought would be fundamental requirements. My initial reaction was fairly negative, after all I was just after a link and my site was in developmental stages, however I thanked him kindly for his advice and set about addressing all the issues he had raised. To be honest, his comments did not tell me anything that I did not know, but it was really helpful to know that someone else had looked over my work and could see the gaps. I am now confident that the site is better-informed and more complete. Objective criticism is a lot more useful than someone telling you that you have a 'nice site'.
My SERP continues to remain very high for my one main keyword - I am starting to look at supplementary keywords now that the main one is almost always in position 2 or 3 on page 1. I did however discover that 'Bing' did not seem to know who I was, even when I searched for my domain itself - rather neatly, the results from the failed search gave me the option of submitting the domain to Bing - I will have to check in a few weeks to see if Bing is reporting me in results - looks like I had better check all my other domains in case Bing needs to be enlightened...
Finally, I am very happy to report earnings from Adsense on the site that equate to 6 months hosting fees, and a growing revenue from eBay partnership which I am increasingly confident will yield a net profit at the end of the year.
My plan remains for next year to be up and running with an 'unlimited' hosting package and repeat this experiment at least two or three times over. I cannot yet reveal my domain or keywords that I am working on as I have yet to purchase the domains I will need. I firmly believe that with several sites all working similar niches I can produce a small revenue which, once established will just passively earn for me for the future.