I received a second request from an agent!

Over the last year I have worked on sending query letters to agents. I will be the first to admit that my first attempts lie somewhere between abysmal and wretched. As I have improved my skill at writing query letters, and learned a great deal about the industry, I have shorted and condensed my query letter with each attempt. Recently I carefully selected 5 agents to query. I studied each agent and revised the letter to be specific to them.  It is now a week later. I have received 2 rejections, and a partial request to read the first 50 pages.
With no small amount of effort, I quelled my excitement and sent the fifty pages. As much as I hope for more, I know the odds are against me. To date, I have sent around 100 query letters. (About 10-30 per round) Although I doubt I will be accepted by the first person who requests my work, I see this as a sign that my query letter is improving.
Of course . . .  I will more than happy if she decides to represent me.