It doesn't necessarily depend on the purpose of the site, it depends more on the purpose of the page. What is the primary action that you want the user to take when the land on your landing page? Make it obvious to the user. Secondary calls to action are also appropriate, but if possible, they should complement and be located next to the primary call to action. Secondary calls to action should be less prominent than the primary call and represent a lesser commitment.
As an example, a landing page that we've all seen in one form or another:
- Purchase Now - The primary call to
action
- Free Trial - The secondary call to
action
- Learn More - Another secondary call
to action (or if you prefer,
tertiary)
Anything that doesn't complement, explain, or direct attention to the calls to action should be minimalized or eliminated from the page.
The most successful landing pages are those in which the page's calls to action coincide with the goals of the user.
However, no matter what anyone tells you, including me, the best course of action is to test which method is more successful so that you have objective results.