I've been on the fence for years about whether headshot drop-offs are for me.
I'm not a big fan of the drop-off services in which your headshot/resume is grouped with those of a bunch of other actors and dropped off to a plethora of theatrical and commercial casting offices. You can definitely get lost in the shuffle and the only real purpose of these companies is to drop off to as many casting offices as possible while charging you fairly high prices for the service, in my opinion.
I've always thought that quality over quantity is the biggest bang for my buck.
I recently re-visited my target list of episodic and feature film casting directors. And, in coming up with year-end goals with my career coach, Dallas Travers, I made a goal to book 3 co-star roles by 12/31/2010. So, we looked at all the ways I could be marketing to CDs and I decided to add drop-offs to CDs back on my marketing list BUT only drop-offs to those offices I could walk into so they would get to know me. And, my only costs are the reproduction and gas costs.
It's helping me in many ways: I know where the casting offices are, I get out of the house, I am doing something productive for my career and I'm making myself known to the casting offices I want to work with.
Again, quality over quantity.