Using long tail keywords in website is best way of optimization because it makes more keywords combination as compared to single word keywords and next one thing is that Google search engine penalize only that website are targeting comparative single word keywords.
Definitely, you can do it, because long tail keywords are less competitive as compared to shorter one. Secondly less number of companies use long tail keyword for their business so it is very easy to target them to get rank for a certain website.
Long Tail keywords are very much easier to rank in any search engines, if you use your long tail keywords with exact matching url, then your page will be ranked in first page.
Using long tail keywords in website is best way of optimization because it makes more keywords combination as compared to single word keywords and next one thing is that Google search engine penalize only that website are targeting comparative single word keywords.