Guest post by Chris Hexton, co-founder of email marketing startup Vero.

Starting an internet company really boils down to two things: building stuff and talking to customers.

The engineer in me loves the fun of bashing out new features. While building a kick-arse product is no easy task, the fact remains that talking to customers is pretty damn vital. If you don’t, you’ll end up building something no one wants or, even worse, building something no one ever hears about.

There is one really cost effective way to automate your customer communications and convert more customers. It’s called email remarketing (or lifecycle email marketing), and refers to the practice of sending emails to your customers at the right point in the purchase funnel (the steps a customer goes through from first becoming aware of a product, to converting into a sale or sign up).

There are lots of great campaigns you can run and test but here are three tips I think every startup needs to follow to maximise their conversions using email remarketing:

1. Setup your killer remarketing campaign

This campaign is your bread and butter; the email campaign that will win you more conversions than any other campaign in your arsenal. You know better than anyone what the key steps are in your business’ funnel from the first visit to purchase. Where in this funnel is the highest drop-off? Do 95% of customers drop off on your checkout page? Do only 30% of customers activate and actually install your software?

Whatever it is, setup an automated email that reminds customers to complete this step. Keep the email short and make it casual. Send it from one of the founders, not a ‘no reply’ address and I guarantee this will increase conversions virtually instantly.

2. Segment on one key variable

Pick the most relevant attribute for your online business, capture this information and actually use it to segment your killer campaign. For a clothing store, like ASOS, this is recording whether a customer is male or female. For Vero this is determining if you have an e-commerce store or SaaS product. If you’re looking for a simple way to collect this information when a customer signs up or subscribes to your mailing list, ASOS provides the perfect example.

3. A/B test a campaign, today!

A/B testing works. But, although most of us do a great job of testing our landing pages and product features, we don’t bother to test email subject lines or content properly.

Next time you send any email (a newsletter, a password reminder, a welcome email) set up an A/B split test. It will force you to re-think the message in the email and any missed opportunities to improve your content. Simplify your call to action, alter your subject line, try a plain text email — all of these things can improve your conversions immediately. For a real-world example, check out the results seen by Flightfox.com recently (it doubled its email conversions using an A/B test).

What are you waiting for? Go do it!

Implementing these three ideas won’t take you more than a few hours, but the pay-off will be substantial.

Email marketing is by far the most cost-effective marketing channel to use, yet nearly all startups fail to email their customers enough. There are lots of ways you can be both helpful to your customers and deliver significant results for your company — these ideas are just the tip of the iceberg.

My last word of advice: the focus here is on action, not perfection. As with all things online, don’t over-optimise early — start testing your email remarketing campaigns and grow from there.

Chris Hexton is a co-founder of email remarketing software Vero. He spends his days helping online businesses to optimize their email marketing and use it effectively to maximise their profit. You can catch him on Twitter via @chexton.