VirgoLab

One reason that is often given for building recommenders, particularly in the context of a digital library, is that it is supposed to help address the information overload problem. However, one can easily argue that the converse is true.

Thus, a recommender actually adds to the information overload problem and thus exacerbates the attention deficit problem that Carr complains about in his article.

perhaps we should focus on what’s in front of us instead of fretting about whether we’ve reached 100% recall.

Social Media is a lot about sharing.

As we start to experiment with social software we realize that sharing is good and soon become open to sharing a lot more. There are some things though, that just seem semi-social. What I mean by Semi-Social is roughly "Thing I would not mind sharing with a small group of trusted friends and family members".

纵观互联网的所有商业形式，都源于三种简单明了的商业属性，那就是媒体属性、市场属性和工具属性。

所谓的“社会化网络”更趋向于互联网的媒体属性，本质上说它依然是一个传播渠道，不同的是传播的载体是人而不再仅仅是信息。基于 这样的特征，“社会化网络”的“商务”价值也应该主要集中在网络营销业务上。如果真要考虑“社会化网络+电子商务”的模式，也需要（事实上也不得不）将二 者区别开来，不能过于交织甚至混为一谈。

媒体属性指向网络广告业务，或者说网络营销，典型代表是门户网站、Google、Youtube；市场属性指向电子商务，典型代表是Amazon、eBay、阿里巴巴，也包括虚拟物品销售；工具属性指向付费服务，典型代表是Flickr，包括各种SAAS产品。换句话说，所有能让你靠互联网赚钱的买卖，只有这三种。

Some interesting stats from the paper: Google executes 100k MapReduce jobs each day; more than 20 petabytes of data are processed per day; more than 10k MapReduce programs have been implemented; machines are dual processor with gigabit ethernet and 4-8 GB of memory.