Relevance: The future of job advertising

It seems to me that the future of job advertising will be relevance. Relevant ads sent to relevant people. What is needed is the capacity to deliver narrowly targeted advertising messages in places that have communities or groups created around very specific common interests. This gives us the ability to reach groups of people who are relevant to specific job requirements. Maybe this will mean building a network of blogs, and categorizing them in some way. For example http://www.anshublog.com/ has a small audience built around ERP and SaaS. If you want to hire good talent in this area, you may want to include this blog in your publishing list. Two companies who are teaming together to start doing something like this are JobThread (http://www.jobthread.com) and Arbita (http://www.arbita.net)