This is a send up to entry-level Project Managers. At 0 - 1 year of experience, vetted for the core PM skills: intelligence, work ethic and common sense, Associate/Assistant Project Managers are an invaluable part of any PM team.
There are more moving pieces, parts, assets, paperwork and points of contact to be managed than ever before in building Web sites or developing online advertising campaigns today.
An APM can elevate the performance of an entire PM team. Beyond the direct benefits of the myriad of listing, vetting, and distributing of tasks that APM's take on, they enable other members of the PM team to focus on higher-level activities and deliverables. Further, their presence gives more senior members of the team an opportunity to mentor and manage to the benefit of all.
I love having these smart, motivated, young guns around. Their on-boarding helps validate the efficacy of tools and methodologies, and contributes to process and tool evolution. These new-entrants also bring a native's view of new technologies and trends and inject much-needed energy into the "old school" of some agencies. Mike Carlton, of Carlton Associates Inc, is particularly compelling on this topic and related ones in his piece, Who's Going to Do the Work?
The best APM's invariably gain mastery of the support skills in a few months (right, if they can't then their probably not cut out for PM'ing?) and begin taking on higher-level tasks themselves. This doesn't hurt the agency bottom line and definitely raises the bar for everyone. Further, there's nothing like someone w/half the experience and salary, nipping at heels to keep a team on their toes - especially those prone to sluggishness (you know who I'm talking about, right?).
From an overall agency perspective, a junior PM role, with exposure to so many aspects of an advertising agency, is the perfect farm league for feeding all the disciplines in an agency. One could go so far as to say that all entry-level employees would do well with a rotation in PM.
If you've got 'em make the most of it. If not, you would do well to add an entry level PM if you are able. The job/agency you save, could be your own!