Email marketing is still one of the most effective forms of digital marketing available, and can allow you to reach more of your target audience than any other marketing platform. Roughly 22% of emails get blocked or lost in spam filters, but that still leaves an average of 78% messages delivered.Not only does it have a high conversion rate, but it's great for increasing repeat traffic to your site. Emailing offers, new products, or teasers of your latest blog posts, gives people a reason to come back to your website. Sometimes, just popping up in somebody's inbox at the right time in their buying cycle can be enough for them to make the decision to buy from you.When you use other online marketing channels, you rely on their service rules. Facebook can decide to decrease your reach to encourage businesses to pay for ads. And Google's algorithm changes so fast you might be reducing your page rankings without even knowing. But with a large network of emails, you can still reach out to people and promote your business.But it's also important to play by the rules. Most bulk mail sending platforms frown on the use of purchased email marketing lists, and you are likely to get penalised if your mailshots result in large amounts of bounces, unsubscribes or spam complaints. So it's important to build your own targeted lists of people that have interacted with your business in some way, as they will be familiar with your brand and less likely to view your emails as unsolicited.There are lots of ways to build a list, from harvesting the email addresses of existing contacts in your inbox, to collecting leads through the use of 'content upgrades' on your website. You can then set up 'drip' campaigns to feed new subscribers with an automated series of useful emails that will help establish you as an expert in your field – and then once they're ready to purchase, you'll hopefully be at the front of their minds.