This afternoon, I got to take a nice long walk in the sunshine (it's about 75 degrees here today) to the post office where I sent off my first batch of commercial agent letters. I sent out 17 this time, and now it's just wait-and-see. With the new postal rates, it cost 97 cents to send each one out. So, in addition to being very time-consuming to do a mass mailing to all 150+ agents, it is really cost prohibitive - especially considering most people have to do several such mailings before they get an agent. Yes, it might take longer this way for me to finally land an agent, but I think it more likely that I will get a good one this way.
So, I will just move on to other things and give this mailing about a month or so. If, at that time, I haven't heard back from anyone, I'll (mostly random at that point) choose several other agents to send to.