Amazon are willing to pay £5 for details of my Facebook friends

<JustWondering>
I got this email last week:

Glossing over the fact they ignore our 16+ year relationship and can only address me as "Amazon.co.uk Customer".
I don't think I can recall another business being so transparent about how much access to my Facebook data is worth.

Exactly what data?
We'll, here's what they want to know:

So, that's my details, plus my friends details, their birthday's and their likes.

Wow. At the very least, Amazon think they can make more than £5 extra in profit by being able to remind me that my friend has an upcoming birthday and suggesting things I can buy for them as a gift.
Plus many more things as well no doubt.

Yes, there's a potential benefit of potentially improving relationships by helping make sure I don't forget a birthday and making it easier for me to give (send?) them an appropriate gift based on their likes.
However:

• Do I really need yet another service sending me emails about peoples upcoming birthdays?
• Am I really likely to need the present suggestions for my close friends?
• Based on Amazon's ability to mine large amounts of data, what will be the long term consequence of me giving them this Facebook access?
• Is £5 really enough to get lots of people to sign up to this? If not, then I wonder how much would be?
• Do people look at an offer like this and think about the data security implications? Or do they just think "free money"?

</JustWondering>