If your goal is to increase your website's profile in the search engines and on the internet generally, you will want to use a combination of improving your on site optimisation (looking at keyword density and title optimisation, etc.) while at the same time increasing your link popularity. In my experience you have a lot more control of the latter, since the search engines are constantly changing their algorithms regarding on site issues but link popularity will always give your site a boost in the rankings. And the good news is, you can increase your link popularity for free. Just be prepared to put some time and effort into this campaign.