As a PM, a big part of your job is collecting and triangulating data. Where does that data come from?

Customers (short term)

Sales feedback
Support feedback
Usage analytics
Customer interviews
Focus groups
Churn reasons

Business (medium-term)

Where does the business want to go?
Where does the board expect to go?
Where are the new markets and new opportunities?
What are competitors doing?

Your Vision (long-term)

Where do competitors seem to be going?
Where do technology and culture trends seem to be headed?
What framework do you have to help rationalize the world?
What niche do you want to fill?
What novel innovation can you and your product/company deliver?

It’s a feedback loop between all of these sources. Customer and business data should inform your vision and your vision should be a lens by which you filter customer and business data in and out of your plan.