Just directory listing will not give you proper results. You should have good keywords in your site's meta data and meta keywords to get your site in search engine top 10.
I could not understand your point about less keywords. what does mean less keywords and how are effective these to bring more traffic. plz
A hope at least you have an idea in what topic do you want to build a site. Then you should choose the most relevant word you would search for in that topic. Let's say its 'directory'. Then use a keyword tool and search for other keywords that Google thinks to be relevant to that word and try building links using one of those words as anchor text. But don't use more than 3 or 4 keywords.
all key word is value able but remember if you have your key word related site back link (it may be from directories,article submission, forum sites), that will help you for your site rating....thanks.