Well, in the Italian market is very difficult to find a literary agent available to work with unpublished authors. There are three types of agents.
The first type is mostly a provider of literary services (evaluating, reading, and correcting manuscripts, some promotion, no more. They make profit mostly on writers, since you have to pay to obtain their services. I strongly discourage you to use them.
The second type is more professional, works mostly with published authors but sometimes looks for new entries. They do not promote authors, but manuscripts, that is, titles. They search for publishers and sell the book to them by taking a percentage out of the revenue of the author, not the publisher. It is a good start for unpublished or self-published authors, but one success does not give any guarantee that you will sell the second book.
The third type are very professional: they works ONLY with published authors, possibly famous ones, and they take care of all the aspects related to the author him/herself: promoting boks and author, participation to events and show, ads and any other activity, as a partner. They take a significant percentage of author's revenue, but if you are served by them you are rich: you can survive :)
In Italy, three agents of the third type has the 90% of published successful authors. That is why I am trying to be supported by one of them ;-)
My agent Triada US, marketed my first two novels and is reading my third. I went the agent route because the big publishing houses will not review non-agented material. I shopped around my first novel after the mainstream publishers said no.