One aspect of a city's economic development strategy is local employment. In particular, local employers must be able to grow their employee base as business success necessitates.
In the technology industry, a significant segment of the employee base has a professional background, and specifically technical expertise. Thus, finding the employee with the right combination of technical skills and soft skills can be a challenge. When presented with a job requisition, I have observed that corporate recruiters begin by exhausting their own network before approaching alternate resources (e.g. job boards, third-party recruiters, etc.) The reason is that candidates sourced from an existing network often results in better quality (not to mention faster and less costly) placements. In fact, based upon this phenomena, many employers have established referral programs that incentivize their own employees to make recommendations from their respective professional networks. After all, employees are generally excellent judges of a potential coworker's technical skill, and furthermore would not recommend someone who couldn't pull their own weight or was difficult to work with. Thus, corporate recruiting efforts benefit from well-networked employees.
In the Door64 community here in Austin, many human resource managers have encouraged employees to participate so that the effective hiring network reach for the entire company expands. It's a win-win scenario: each technology professional builds his/her own network of local colleagues which provides additional career security, and the company gains a premium qualified referral base for hiring the best talent.
Cities should encourage the creation of grass-roots niche communities so as to foster these professional networks so local businesses can efficiently find the talent they need to succeed.