I built 2 almost identical websites in separate niches in November 2012. (By identical, I mean that they have same layout and design)

One has had a lot of seo done including quality backlinks, social media etc
The other has not been touched.

To date, they both rank in similar positions within Google, they both have a PR0 and they are getting similar search results.

Can anyone explain why this should be? It seems as though I have wasted a lot of time and effort with SEO only to find that it hasn't really gained me any advantages.

By the way, both websites are in high competition niches.

Thanks