Autor: Daniel Rabinovich

Relative color

I’m amazed at how many people think that colors are absolute, meaning the same RGB value will be perceived as the same color in every condition. It’s definitely not like that. Lighting conditions and the proximity of other colors and shapes greatly affect our perception, and our brain performs an enormous amount of corrections.

Consider this optical illusion:

Despite squares A and B are the exact same color, they are perceived as black or white in the proximity of other colors. In Color Theory, this is called «color context».

Lighting conditions are another source of relativity. When using our eyes, our brain learned what lighting conditions we’re on and automatically adjust perceived colors. Digital Cameras have a tough time understanding what our brain is automatically correcting. That’s why we’re asked to adjust white balance when taking pictures. The following pictures show the same object in the assumption of three different lighting conditions (tungsten, fluorescent, and sun):

Why is this relevant to an e-commerce company like MercadoLibre? Because we need to extract product colors from user-uploaded pictures with unknown lighting conditions and therefore, unknown colors. This is a non-deterministic, complex, and beautiful problem to deal with. We’ll keep you posted.

Daniel Rabinovich

The Art of Fielding

The Art of Fielding

I´ve just finished The Art of Fielding, by Chad Harbach. This slow and great novel was last September’s Amazon Book of the Month. It’s a story about baseball, campus life, romance and friendship. This is not a review (here’s a great one from NYTimes), but a small compilation of my favorite quotes from the book (love the Kindle «highlight» feature).

Putting Henry at shortstop – it was like taking a painting that had been shoved in a closet and hanging it in the ideal spot. You instantly forgot what the room had looked like before.

Henry closed on it quickly, absorbing it into his glove with the thoughtless ease of a mother being handed her newborn baby.

Locker rooms, in Schwartz experience, were always underground, like bunkers and bomb shelters. This was less a structural necessity than a symbolic one. The locker room protected you when you were most vulnerable: just before a game, and just after.

A good coach made you suffer in a way that suited you. A bad coach made everyone suffer in the same way, and so was more like a torturer.

Couldn’t resist a techie’s note: the book was bought on the new HTML5 Kindle Store for iPad, a clever way Amazon has found to dodge Apple’s 30% «in-app purchases» fee.

Daniel Rabinovich

A variation of the Classical N-Queen Puzzle

I’ve always loved the classical N-Queen puzzle. The goal is to place eight chess queens on an 8×8 chessboard so that no two queens attack each other.

Here’s one solution (92 in total):

Some time ago, a clever friend asked me if the number of solutions would be greater or lower if the goal was to place 7 queens instead of 8.

– «Greater, of course» – I replied.
– «And if you had to place 6?»

Then I realized that the number of possible solutions would peak at some point and then it would decrease until it hits 64 (the number of squares = the number of solutions if the goal was to place only one queen).

The highest number of solutions occurs when the goal is to place 5 queens.

I had a lot of fun coding the solution, using recursion and backtracking.

Here’s the source code on GitHub.

Daniel Rabinovich

Sharing ideas with Vint Cerf

Last week I was lucky enough to meet Vint Cerf, one of the fathers of the Internet. Among many other achievements, Cerf worked on the protocols that later became TCP/IP. Not many people in history can claim a larger contribution to mankind. Unsurprisingly, despite being 72 he’s full of energy, humility and sense of humor. I had the honor to share a panel with him, along with Santiago Bilinkis and Ariel Muslera.

I based my talk on the study of Kevin Kelly, the legendary editor of Wired Magazine, referring to some of the technology trends that will probably reshape the web as we know it, and generate immediate winners and losers. The line between opportunities and threats has never been thinner.

The first encompassing trend is the proliferation of screens, as Kevin Kelly would describe it. Just a few years ago we had two screens at home: a TV and a PC. Now we carry three connected devices: a laptop, a tablet and a mobile phone. Connected devices are not just computers anymore. They are TVs, running shoes, freezers, dispensers, airplane seats, etc. The “internet of things” is finally here. If a service is only prepared to run on a single device, it will be quickly kicked out of the game. Mobile screens are often equipped with a GPS, and connected to social networks. This combination, often called SoLoMo (Social + Local + Mobile) is rapidly changing the rules of e-commerce. In MercadoLibre, we have spent more than a year rewriting our platform to build a common and open service layer to fulfill the needs of many screens. If we hadn’t made this decision, we’d have found ourselves in a strategically lost position.

The second game-changing trend is the explosion of data. In 2011, 1.8 Zettabytes of data will be created or replicated. That’s about 4 million times the content of the Library of American Congress.  Zuckerberg’s Law stated that the amount of shared data will double every year. This year, the number of connected devices will be larger than the human population on the planet. In a platform like MercadoLibre, there are 50MM search queries a day. The key to a good search is data, algorithms are becoming commodities. One difference between winners and losers will be the ability to master “big data”.

The third key trend is that Accessing is better than Owning, when the entry barriers are low enough. Owning is expensive and distressing. Why would I want to own a book if I can have it whenever I want? And what about a WebServer, a Network service, a CRM platform? The difference between a product and a service is blurring. Why is this a game-changer? Because entry barriers are imploding, it’s become too easy and cheap to launch a product. If a current leader is not offering a good balance between value and cost, a strong competitor may emerge overnight.

However, is there anything that is not changing? Are there value creation mechanisms that were great ten years ago and will also be great in ten years?

Reputation is one of those constant values. It´s not easy to replicate. A seller in MercadoLibre has a good reputation because she sold a thousand units to different buyers. This is helpful to the next buyer because the reputation is curated by the brand and can’t be self-proclaimed by the seller. There is a genuine value creation within a large ecosystem. You are on Facebook because your friends are on Facebook. Network externalities are very powerful. This was true ten years ago and will be true in the next ten years.

Attention is another basic value that hasn’t changed and won’t change as a value source. “Where eyeballs go, money will follow”. Countless ways of exploiting attention will emerge, as new screens and new ways to interact with them continue to appear. Nonetheless, one constant remains: people will still be willing to pay for attention, and not just advertisers. Attention, like reputation, cannot be easily copied.

As a conclusion, despite the fact that technology is evolving amazingly fast, there are some constant value sources that remain as strong as ever. If your service is based on a friction imposed by the current technology, you should be really worried and doing something about it. On the other hand, if you’re offering a service that relies on a true source of value, change should be more an opportunity than a threat to you. In addition, behind all these changes are human beings. Maybe talent is the most constant and important value source of all.

Daniel Rabinovich