If you are trying to break in with brokers, nothing can possibly substitute for a warm introduction. See if you can figure out a way to get one. Perhaps that means using LinkedIn to see if you have a connection - you might be surprised to find a personal one, which is even better than a professional one. Or, if you are already networking with other professionals in the market, like property managers, lawyers, etc., they often have connections with the brokers in the area. Or you can ask other investors.
It is very difficult for someone to turn you down when you come through a warm introduction, which is why they are great. But your job does not stop there. First, make sure that the introducer does a "double opt-in" intro, where they give the broker the chance to say no to the intro. Usually, they say yes, and once they have committed to this, they will generally engage with you. This is far better than the person simply introducing you as a surprise to the broker. Worst of all is the "use my name" non-intro, also called a "referral." Better than nothing, but not very effective. So make sure you ask for the right kind of intro, the double opt-in.
Next, you had better make sure that you look good if the broker decides to google you to see who you are. It's best if they can find something that shows you are an investor and not just some guy.
Finally, if you get the opt-in, you had better follow up. You risk not only your own credibility but that of the person who introduced you if you don't follow up.