The kinds of leads that you are likely to get for free are ones that have been gathered in a scatterspray way – they could be poorly targeted, or in some cases even people who have not opted in at all. If you contact leads like this, then you will be putting your brand at risk, because you could end up in trouble with your web hosting provider, or the law, for unsolicited marketing. Alternatively, you could end up contacting people who might otherwise have converted, but who come to view your brand as a spammer because of the way the initial contact was made.
The main website a lot of people use when they are online is social media. These websites are where you can sit there and talk to anyone around the world that you know, and chances are that most people you know have an account on these kinds of things. You’ll want to make sure you do some looking into making a business account, because marketing through your personal profile may not do so well for you. Social media sites are free to use, but they also have ways you can pay for ads that go out to people.