approach them in reverse order, starting with your least favorite, (but perhaps more available) agents first then move up the scale?
Whatever you do, never query 100 or more agents all at once. I wouldn't even do as few as 30 at one time. Bad move. Here's why: You have to look at your query as a work-in-progress, as something that can always get better. Consider your literary writing. Have you ever written
something, let it sit for a while, then returned to it and found so many things you wanted to change? Things that you knew would make it stronger. You might even find mistakes or errors which you didn't catch the first time. The same is true for your query letter. So, copy and pasting a flawed and/or weak query to every agent you're interested in could be a huge
There's also the possibility that your original query approach is all wrong or weak and needs to be overhauled. You'll discover this after you've sent your query out to 30 or 40 agents with no positive responses. If you think your query is as good as it possibly can be and you've sent it out to 40 agents who are interested in the type of story you've written you should get at least one positive response. If that doesn't happen, you really should reconsider your query. A total rewrite might be in order.
My experience has been that a query or pitch can almost always be improved. You never quite arrive, if you understand what I mean. A query pitch is always being honed and sharpened continuously over time. Your best bet is to discover this incrementally on the basis of testing. You might, however, want to start over from scratch for a fresh new perspective. For this reason, you can see that it is unwise to send out your first query to
too many potential agents right from the start.
The opposite approach of sending them out one at a time and waiting for a response is simply impractical. Seeing as agents take (in real life) at least 4 weeks to respond, if you planned to query 40 agents you're looking at 160 weeks before you hear back from all of them. Like I said, impractical.
The number "40" is used in the above example because when cold calling agents you can only expect about 2-3 percent to respond positively. A one out of forty responding positively is a success rate of 2 1/2 percent.
So, those are the reasons sending queries out in batches is the best approach to take. But, having said that, I still wouldn't blindly copy and paste each query you send out. Finding your pitch errors early on is still to your advantage. That means you should read each and every query before you send it out. After reading 40 query letters, you really should find most, if not all, of the fundamental flaws. Even better, have a significant other review them for you. Other people catch errors that you, as the author, are blind to since your brain and eyes are the same brain and eyes that wrote it.
As for sending out your batches first to your 3rd level agents followed by 2nd then 1st is that your 1st level agents are going to be those that work for the highest ranking agencies. These agencies get an unbelieveable number of queries. They have a much larger quantity of good material to choose from than 3rd level agencies. The level of competition on the fist level is obviously greater. It is better to have your very best quality material being sent when you decide it's time to inquire at this level. (Of course all this changes if you end up being recommended by someone to one of these top level agencies. In that case, you definitely do contact the top level agency first.)
The best way to beat the competition when you apply at these top level agencies is to approach them with an offer already in hand. I know this sounds smarmy, but it really does get their attention.
So, once again, here's how the strategy works: Send out queries to your 3rd and/or 2nd level agencies. If you receive an offer of representation move immediately toward the top level agencies and tell them you already have an offer in hand, BUT, you want to consider them (a top level agency) because you really prefer them and their agency and don't really want to go with the other agency unless you have no other choice. Whatever you do, don't reveal the name of the agency that has made you an offer. The hope is that they will assume it is a top level agency like themselves. After all you contacted them, it is safe to assume that you are contacting other top level agencies and that one of them made you the offer. In any case you don't want them to think or find out that the other agency is a single person little known shop.
Don't assume that pitting one agency against another is breaking some rule of agency etiquette. Agencies themselves do it all the time when they pitch books to publishers. They're more than happy to have an auction spring up. I knew an author who had a firm offer from Doubleday, but instead of signing a contract with them he immediately wrote to four other top level publishers and in his pitch informed them of the offer from Doubleday. All four publishers sent him contracts begging him to sign with them. He essentially created his own auction. He eventually went with McGraw-Hill.
Hopefully these strategies will be of help. Good luck everyone!