The document discusses how social media and open data can be used to create economic opportunities and engage citizens. It highlights the concept of "cognitive surplus", where people have spare mental capacity that can be used to create new online resources. Examples mentioned include hyperlocal blogging, data projects from BeVocal, and tapping into raw data through initiatives like "Timely Information". The document argues that combining cognitive surplus, open data, and digital tools allows citizens to participate in new ways and supports the growth of the digital economy at a local level.