I think that is a great resource! I was so glad to stumble upon it in my searching. Jason is doing a great job. This network isn't looking to replace that as obviously this is going to be more about social/networking interaction among local marketing professionals. Though I do hope it becomes a resource for information as well.
One of the Search Engine Optimization strategies that is very important is in linking. You should be trading links with relevant Websites that cater to the same audience that you are targeting. You should also be searching the Web for relevant directories such as The Philadelphia Marketing Directory to add a link back to your Website. There are also thousands of general directories that you should consider adding your Website to.
Most website should include a resource page or section that is linked from their homepage. This resource area should include relevant Websites that would be beneficial to your audience. Make sure that the links open in a new browser so you don't lose your site visitor. In exchange you should be linked from the Websites that are listed in your resource section. This increases traffic in two ways, 1) potential business directly from users that click on your link from one of these Websites. 2) The more relevant links you have pointing to your Website the better chance of receiving higher rankings from Search Engines, most notably Google.