When it comes to holiday marketing campaigns, email is one of the few mediums that's universally proven to drive revenue online. Across all industries, it's shown to produce $38 of revenue for every $1 invested. And that's not all: Data from Soundest shows that on average, email drives an average of $446 per campaign in the United States. That same data set also showed welcome emails can boost orders by as much as 93 percent.

So what can you do this holiday season to drive more online sales via email? Let's look at five basic strategies you can implement right away.

1. Create ongoing email journeys to nurture new leads. A series of automated emails that educate, inform, and entice a new subscriber can help nudge that person toward conversion over the course of the holiday season. Include helpful how-tos, sale information, and notices around final delivery dates to encourage a sense of urgency.

2. Re-engage those with abandoned carts. If your shoppers left items in their virtual shopping carts before checking out, leverage that data and follow up with a discount or "come back" offer to get them to return to your website and complete the purchase. A 70 percent cart abandonment rate is average for online retailers, so there's a large opportunity for follow-up emails with this demographic.

3. Offer fast, free shipping. Email offers promoting a limited time free shipping offer might be just what your customers want and need. Survey data shows that 80 percent of US shoppers say speed and cost of shopping are a major factor in determining where they shop online.

4. Use stock notifications as a way to re-connect. Emails that let shoppers know when certain items have been re-stocked or are about to sell out taps into FOMO (Fear Of Missing Out). During the holidays when online shoppers are looking for specific items and are in a ready to buy mindset, these emails can help seal the deal.

5. Give context in email. If your website largely uses mock-ups or standalone product images, you can use email to add some context with videos and visuals. Show your offerings in use by the target demographic and let the subscriber envision him or herself using the products, too.

The bottom line: Email needs to be part of your holiday marketing strategy this year. Test some of these tactics and see which ones produce the best results during the 2017 holiday season.