If a large number of long tail keywords in your site have had good rankings, will they really help improve the ranking of your core keyword?
Long tail keywords will hep in improving the overall ranking for your site. It will supplement to PR effort of your main keyword
basically long tail keywords like 5 to 10 words helpful to improve ranking. You can use your target keywords and other secondary keywords in it.
Well it depends on a lot of factors as an example suppose you are a SEO Company in US targeting the keywords "SEO", "SEO Company" and "SEO Company US". If you optimize your page for "SEO Company Us" and also build links with these keywords it will not only rank you for "SEO Company US", but will also improve your rankings for the other main keywords "SEO" and "SEO Company". But suppose your main keyword is "SEO" and you are targetting "copywriting" and you have optimized your page completely considering the keyword "copywriting" and you build links for that keyword only then it won't affect much your rankings with the main keyword "SEO". However, if you rank high for other long tail keywords then it will definitely improve your link juice to the main keyword pages but as I said ranking for main keywords would still depend on many factors like the level of competition and other factors.
it very well may. to get lot of long tail keywords ranked, you would need a lot of backlinks to your site's main page as well as inner pages. lot of it depends on your overall layout of the site and how your inner pages link to the main page. in other words, your internal linking is very important in this case. if you have all the long tail kw spread around with many inner pages and if all the inner pages link to the main page with your targeted core kw anchor text, then you get good seo boost for the core kw. you however would need to do link building for the main kw and cannot just reply on indirect link juice form long tail terms.
what you can do is optimize your website for long tail keywords but still optimize it for your core keywords. There is no guarantee that just because you have ranked high on long tail keywords, you will already rank high on your core keywords. After all, the competition for core keywords is tougher.
The long tail keywords optimize your site and create contents according to the search queries and attract visitors to your site.
Long tail keywords, because there is a much more lesser competition, you will rank fast. Why not try putting your other keywords under your long tail keyword. Will surely help you.
I think long tail keywords have a positive effect on the site's SERP if they also include the broader keywords that are most commonly typed in the search box. It also depends on the competition in your niche.