Most of my sites have a very successful long tail -- high quantity variations with lower traffic each. Is there anyway to increase the success of my core keywords? ... even in a competitive area?
Long tailed keywords will have much less competition therefore it will be easy for you to rank for them quickly. Short tailed keywords have much larger competition therefore you would have to do more work in order to rank for them. Build links and links and links, oh and make sure that they come from high PR sites.