Was at SDCC and let me tell you, LEGO has rapidly risen within about 3 years to become of the most RIDICULOUS retailers at Comic-con for their practices (like Hasbro and Mattel). The doors opened around 9 am each day and people were charging for the LEGO line to buy the Comic-con exclusives. It's sad too because LEGO has always been about making their product readily available to all and just recently they're starting to cater to that select collector market....but you also feed the scalping machine that keeps items out of collectors/fans/kids' hands.
The biggest problem was a strange business model for their exclusives. Ultimately, like others, it came down to quantity. They only made around 1000 of each FOR SALE exclusive set (Batman '66, Rocket's ship and the Ghost) and sold only 200 each day. Yet, they made 1750 of each Mini-Figure and gave those out for free with the only requirements being waiting in line and tapping an iPad to see whether you get one or not. Why not make MORE of something that people are will to PAY for?
LEGO was better with the Mini-Figures. They made secondary characters or obscure variations that a lot of people could perhaps care less about...with Bard being on the border of being an uber popular character. The line was also outdoors and LEGO and the security staff did a great job of keeping it civil and getting it down quickly and easily. You waited in line, stepped up to an iPad when called, tapped it to either get a Green "Good Cop" screen or a Red "Bad Cop" screen and either got the figure or not. Pretty fair and simple.
The line inside to buy the exclusives was another story. Chaos at times. No clear end of the line for a while. I heard a story of a little girl nearly being trampled by people trying to make the line (it was also said Lego gave her a ticket afterwards). Lego did the best they could but considering the limit and all the people charging there and to other exclusive lines, it was a little out of control at times. They did end up issuing a token system where they handed out tickets for the number of exclusive sales that day.
Once again, it comes down to an uber popular exclusive/s (particularly the '66 Batmobile) and low quantities. But why make such a low number for something people are clearly willing to pay for? The only true exclusive items I wanted were the Bandai Tamashii Anime color Vegeta and the Mondo exclusive posters. Bandai/Tamashii had plenty of stock, more than enough that they LIFTED the one-per-person limit after the first day and were selling boxes of the items. Yes, scalpers were walking away with boxes of them to sell, but at least there was MORE than enough to satisfy everyone at the Con who wanted one. LEGO should follow a similar model with their FOR SALE exclusives.