(Pictured: The world-famous Tower Bridge features iconic towers, working drawbridge and a red double-decker bus. It also includes 4,295 pieces and costs $240.)
Netbricks currently employs eight people, including Weil. Each employee has a dedicated job, right down to the person who does the all-important cleaning of the returned sets, using a medical-grade technique that's absolutely necessary for anyone who considers the term "used Legos."
Weil said that parents are actually far less concerned about cooties than they are about penalty fees for lost pieces. Netbricks assesses no charge for those.
"Part of our service is no charge for normal piece loss," Weil said, citing a range of 15 to 20 lost pieces for regular sets or 20 to 30 for larger ones. He added that the company's real concern is the malicious actor who "harvests" Lego sets with the intention of selling rare pieces to desperate builders who need that special brick to finish their creation.
Weil would not disclose his company's financial information, but he said that it's profitable on a gross margin basis, and he expects it to be cash-flow positive in six months' time. He added that he's in no rush to see the company get ahead of itself by expanding too quickly.
"We made a decision early on that although there's more demand out there that we can get, we didn't want to take on a huge volume of customers until operations are ready to scale," he said. "If you don't have customer service and structure where you can field all calls, that's not a great way to grow a business."
Netbricks currently boasts 215 "fully active" members, which it defines as members who have rented and returned sets for more than one cycle. The current total is well below the 5,000 customers who signed up at launch, but Weil said that was to be expected because of the one-time impact of the Groupon promotion. The lower number of repeat customers is a more accurate reflection of Lego diehards. And Weil said that Netbricks has been successful in retaining repeat customers, so they must be doing something right.
Netbricks is not allowed to buy Legos from Lego.com, because Lego is trying to discourage resellers. Netbricks buys its entire inventory from retailers (Walmart, Target, Toys-R-Us, etc.).
"Lego is aware of what we're doing and we've had a handful of communications with them," Weil said. "It was nothing atypical of how a top five worldwide brand would work to protect their brand and trademark. Anytime anybody pops up and is using the word 'Lego' in a commercial sense, the Lego company sends out information and notification as to how they would like you to use their trademarks, and that's been the extent of our business to business communication with Lego."
Lego Group could not provide a comment by press time.
"We're focused on providing an experience for big-time Lego fans. We have a lot of respect for the Lego company and their retail model," Weil said.
— By Daniel Bukszpan, special to CNBC.com