Question - Is Keyword Case Important?

The keyword I get from Wordtracker is: (all lower case) "registered nurse resume writing service"

Can I use it on the page as:

(sentence case -first letter capitalized) "Registered Nurse Resume Writing Service"

For the headline and other instances on the page?  Or is it better to keep it exact, fro better search engine ranking?

 

Search engines are not stupid and know that people who search for Coca Cola and searching for the exact same thing as coca cola.  Why would they want to serve different results for the same term.  No Case is not important.  Some SEOs maintain that case is important but I disagree, and I think it is much better to have your web page look good for human visitors.  If you want to test this for yourself, go to Google and type in both variations.  You will see the same number of results returned, and in the same order.