The best stories across the web on media and technology, curated by Leandro Oliva.

1. Why do community news sites, once hailed as the future of journalism, so often flop? (Adweek)

2. Online radio will start serving ads based on your web browsing (paidContent)

3. How does BuzzFeed intend to crack a $1B valuation? By embracing journalism’s past (PandoDaily)

4. The Atlantic Wire taps Sencha to launch a new HTML5 iPad Web app fit for the digital era (TNW)

5. A behind-the-scenes look at how Twitter search works (AllTwitter)