As I mentioned in my last column, email is still one of the top online activities.  Several recent studies keep email in the news.

Silverpop's 2012 Email Marketing Metrics Benchmark Study found, in an analysis of 1,124 brands, that while average open rates are down to 19.9% (from 21.3% in 2009), average click-through rates are up to 5.4% (versus 4.5% in 2009). "Opens by opener," or the average number of times a single user opens up the same email and re-visits the message, is 1.79.  This means you should expect most emails you send to be viewed more than once by your recipient. The report has useful information broken down by industries of the companies sending the emails; computer software firms have the highest open rates, (24.7%) which education companies have the lowest (15%). You may want to compare your own email stats against your industry's.

Message Systems' "Marketing Channel and Engagement Benchmark Survey" found that out of all the delivery channels, 63% of respondents said that email was delivering the highest "return on investment" for businesses over social media, the second most popular channel.

Emarketer predicts a steady trajectory of email usage from 2012 to 2016 and has seen increases in spending on email (in addition to social, mobile, and search). For new customer acquisition, Emarketer says, email topped the list at 83.6% of delivery methods both business-to-business and business-to-consumer marketers intended to use.

A recent Marketing Sherpa survey predicts a 54% increase of marketing dollars to email, further enforcing email's marketing potency.

And my own informal poll in my "Don't Call Us--We'll Facebook You" article showed that 77.5% of respondents prefer to be contacted for business by email, far outweighing any other channel.

With all this data, it's hard to argue against email's place in your digital marketing strategy. Here are five ways to keep up with the times, and make sure your email marketing is effective as it can be today:

1. Offer multiple ways to sign up.

As content proliferates and digital consumption of it grows more and more fragmented, you need to take advantage of all channels to add more email subscribers. According to Marketing Sherpa, Whole Foods generated over 2,000 new subscribers by making email sign-up available by text message or QR code scans.

2. Pay attention to mobile email readers.

With more and more people reading email on different devices, you need to consider how your emails are viewed, and if you're optimizing for a mobile user experience. You can also tap into and incentivize mobile users by sending them emails that tie to recent social "check-ins," or other location-based tactics.

3. Avoid sending email blasts.

Many email service providers advocate sending personalized emails. Email technology now exists that allows marketers to generate highly customized and engaging message content.

4. Test, test, test.

Once you have acquired an email subscriber, he's yours to learn from, and work on to improve conversions and sales. Don't overlook the opportunity to test beyond subject lines, copy, and calls to action.  Test delivery timing, tools, and automation, personalized elements, as well as designs and layouts. Check out the "Look Book," a collection of high-performing email designs Responsys puts out as a means to showcase what works best.

5. Start a conversation, and follow it through to other channels.

There's no doubt that social media will continue to encroach on email's turf, so start working on ways to carry your message from email to other mediums. For example, if an email message gets a high response rate,  you ought to consider also using it on your website, in your ads, or social media posts. "Increasingly, engagement will depend heavily on a company's ability to respond to or act on message-based intelligence," advises Carrie Scott, director of product and direct marketing at Message Systems.

Those of us in digital marketing still recognize the power of email. Don't give it the short shrift in chase of some other bright shiny, but less high-performing object.