I agree with you. Nothing indicates that it's business it wouldn't have had otherwise. Yes, their Twitter account is where the traffic and sales came from, but

I agree with you. Nothing indicates that it's business it wouldn't have had otherwise. Yes, their Twitter account is where the traffic and sales came from, but what part of it wouldn't have resulted in a sale without Twitter is the key element. One thing is sure though: it costs a lot less for them to send tweets than to send emails.