Face to Face will always be better. The reason is because to get to the root of an issue or to what really drives a person, you need to ask WHY 5 times. Only then you can offer a solution that will be irresistible to your prospects.

Let's try with an email survey.

1. What is your biggest struggle when you want to expand abroad?
__________
2. Why?
__________
3. Why?
__________
4. Why?
__________
5. Why?
__________

You look like a freak, right?

Now in a normal conversation, it would go something like:

Oh, your biggest challenge is costs? Tell me more about it.
Yes, i just don't have enough cash flow to open an office abroad.
Where is your cash flow going instead? (that's a hidden why)
It's going into our local activities.
Why do you prefer spending money locally?
Because we get more return on investment.
etc etc..

I'm happy to jump on the phone to test this technique (it feels a bit awkward at the beginning but with some training it becomes natural).
Serena