I went to a small "private" Dropkick Murphy's show a few years ago at Harper's Ferry in Boston. Given that it was a very small venue, the logistics involved with eliminating scalpers was quite easy. Although it does seem that the idea would very easily scale to much larger venues.

The process was quite simple. Online purchases were limited to (2) tickets per customer. This customer then had to provide and ID at the venue door that matched their credit card and order credentials. If such ID could not be provided then said "customer" was not admitted. This ensured that scalping could not take place - plain and simple. Don't ask me how they convinced the venue to operate in such a way, but it clearly worked flawlessly.