Most companies would say a resounding yes to that question, yet the evidence seems to suggest otherwise. For you see research from Page Lever has found that somewhere between 5-10% of traffic to Pages comes from outside of Facebook. That's right, just 5-10%. That's pretty crappy right?
They looked at over 500 Pages with a combined total of over 100,000 fans, and discovered that on average just 7.56% of their traffic came from external sites over a 1 year period.
As with other marketing though it's important to understand where people are hitting your Page from. For instance if they're coming from an external site it's worth giving them different content to people that are regular visitors. This could be the only time you get to convince this new visitor that it's worth sticking around your Page, so don't mess it up.
You can view where your traffic has come from from within the insights dashboard, under the 'Reach' tab. You can easily export this into a spreadsheet so you can keep track of how the figure changes over time.
So how are you promoting your Page?
Maybe I'm old fashioned but I kinda think if a brand has something great to share with me on their website or wherever, they should tell me it on their website rather than sending me to Facebook. If that's the case, why would I ever go from a website (say) to a Facebook page?