Perhaps I'm naive, or simply behind the times, or have faith in the essential goodness (or at least non-badness) of the human race, but I was unaware that a service like this existed:
Woo-hoo! Now you can query 350 literary agents, without even knowing which folks you've queried! Bookblaster? "LitSpam!" might have been a better name.
There are those who have suggested that e-queries are the wave of the future. Services like this seem to guarantee that almost any agent with any sense will soon be refusing to accept them.
I wondered why I was getting so many when every single place on the web that says "Miss Snark" says "no e-queries".
What I've done now is change my email address for all publicly posted sites. That way, the people whom I do invite to send me material get the address I will actually open and read; those that are "blasting" remain unheard--deleted unread.
There will always and forevermore be some snake oil salesman telling you there's an easier way to thinner thighs, getting a book deal, and charming the sox off Miss Snark. If you run the math it's clear what they really want to do is thin your wallet and pray Miss Snark doesn't notice. Too late.