Is it better to link to main page or sub page

[PowerUp]

Hi, I'm going to start my link building campaign soon. Should I approach other webmasters requesting them to link to my main page (ie. index page) or link to any pages with content they find useful to their visitors?

Which method is better for SEO? Thanks.

[jimbeetle]

link to any pages with content they find useful to their visitors

That's it.