Offer to do work on spec: meaning - they pay you if they use it. Consider it an audition where you have a chance to showcase your skills to people who otherwise wouldn't have listened.
While I agree with this point, there is a risk that you'll end up doing a bunch of audio work with no financial benefit. Some developers do "cattle calls" where they write to a bunch of composers asking for specific type of music and then pick what they want to use. You REALLY need to be careful with cattle calls. The WB once had a "contest" where folks could submit music cues for use in a high level IP. Reading the fine print revealed that every submission, regardless if it won or not, would be property of WB. Meaning folks submitted music which the WB now owns.... for nothing.
It's important to also learn how to negotiate, seal the deal and then collaborate with the client to make sure the content is on budget, on schedule and on target. This also helps reinforce the notion that an audio dude's time and craft are worth something. In some cases offering finished tracks on spec can negate some of these important lessons. But Max is right - this can be a useful, effective way to get a foot in the door, especially when done well.