I sent my CV to some job agents. Most of them did not reply me at all. One agent told me that she could not put me into his database because I did not have a Canadian address. The main reason is that it is difficult for them to arrange interviews and so on.

If you want to find a job in universities, it is a different story. You can contact directly with the professor you are interested in. The professor can make an offer to you even though he has not met you. I got an offer in this way.