[Any customer research involves talking to people, observing and listening to them, collecting all the insights and then analyzing them.]
My favorite customer research tactic (in B2B) is:
1) Find my potential customer on Google
2) Pull up the largest listing that time allows (minimum 100 companies)
3) Call one by one following a script of questions.
Of course, I always offer something in exchange for their kindness.
It takes time, but for me it's always worth it.
[EasyPeasy]