Im in an extremely compeditive niche. If I buy keyphrase domains and put an article or two on them, and link to my main site, will they rank fairly easily? Im talking about extended long-tail keyphrase domains. For instance, say I sell books.... if I buy "wherecanibuybooksonline.com" or "where-can-i-buy-books-online.com", will these sites naturally rank easily for these key phrases? Is this an exceptable SEO tactic?
Rankings for long-tail keyword phrases that receive very few searches will rank with on-page optimization vs. competitive phrases that rely heavily on incoming links with a lot less emphases on on-page optimization. I would be extremely careful about buying a bunch of domains and linking them to your main site - and if you do it, make sure they are hosted with someone else (different class c ip) and I wouldn't advise using the same ownership name for the whois. I would personally add content to your main site that targets the words you want to rank for.
If you are going to link to your main site, make sure you have a new host so as to make sure that the two websites maintain diff. Ips.. And "wherecanibuybooksonline.com" will not rank well only if you write few articles and link to your main site. I think you still need a few more authority websites. What is the page rank of your main site?
Don't buy a domain, you don't need 1. Read my signature. I dominate google page 1 and own multiple spots on it without having even a single domain name