I've made a a lot of websites over the years and normally I would buy as many backlinks as I can to boost my websites up in Google and it has worked but since all these updates Google have made, my strategy no longer works . I opened my own company last year and built a great website with really good unique content that I spent a lot of time writing but again I made the bad mistake of buying loads of low PR/spammy backlinks off eBay and my website has got to page 2 for most of the keywords but just won't move up onto page 1 apart from 1 keyword that I'm not even bothered about. So I'm now thinking about starting fresh by buying a new domain with (-) signs in the middle of each word and then blocking my old domain from Google but still keeping the website there for customers who have flyers/business cards and to save changing the sign-writing on my van. The reason I am thinking about blocked the old domain from Google is because I want to copy the whole website so they are exactly the same on both domains and I don't want Google to penalize me for have duplicate content. Once I have set up my new domain and blocked my old domain from Google I can then start building my own quality backlinks from high PR domains.
This is the only strategy I can think of to get my website to the top of Google apart from deleting the spammy backlinks but there is around 100,000 so I can't see it being possible to delete them all. What I would like to know is am I on the right track because I don't really have much experience in SEO? and if I am on the right track how would I go about blocking my old domain from Google and other search engines without deleting the website?
Thanks in advance and I look forward to hearing your thoughts.