It depends on the context you are using it in! For social news (e.g. reddit et a...

It depends on the context you are using it in! For social news (e.g. reddit et al.), this sort of thing might be a great help at providing personal recommendations.

Here is a fun recent paper from google, about 'Scalable Online Collaborative Filtering' for their personalised news service [http://www2007.org/paper570.php], using MapReduce to run Expectation Maximization. via [http://www.datawrangling.com/google-paper-on-parallel-em-alg...]