One contextual link from a relevant and
high authority site is worth over a thousand irrelevant directory submissions or irrelevant and cheap links
All links are not equal, One link from
a high authority site is much better than many links from a bunch of low authority sites.
is very likely to come up as another relevant,
high authority site.
If you do the data collection and crunching and give
some high authority sites access to the findings afterwards, you can bet they'll do some promotion and inbound linking for you to make sure you have a great sample size.
The more inbound links to your site from quality,
high authority sites, the higher your website — and the individual page on your site to which these sites link — rises in the search engine results pages (SERPs).