The humble subject line has long been an overlooked element of email marketing, often taking a back seat to design, copywriting, imagery and call-to-action refinement during the development of a campaign.

Yet, despite its lowly status on this list of specialist areas, the subject line has actually always been an important factor in email marketing. A good subject line, basically, can make the difference between an email flyer being opened and acted upon or ignored altogether. You can have the best looking email marketing in the world but without a decent subject line to back it up it’s never likely to fulfil its potential.

Now, with mobile devices becoming ever-popular, the subject line is more important than ever to email marketing because of one simple fact;

Smartphone inboxes only display subject lines and from fields.

No images. No preview panes. It’s all down to your subject line. So it better be good.

With the explosion of smartphone use in recent years - the ubiquitous iPhone and Blackberry, along with the rapidly phenomenal Android OS phones (which grew 350% in the last quarter here in the UK) - more and more of us are accessing our emails on the move, or even opting to use smartphones as in-office business devices due to their ever-increasing performance benefits. Smartphones aren’t the preserve of business or the technically-minded, they’re for everyone. And it seems everyone has got one.

Microsoft, which has stayed on the fringes of the smartphone market for the last few years, is moving closer to the launch of its “Windows Phone 7″ operating system - a hi-spec platform that will doubtlessly be backed up by a gargantuan marketing budget when it emerges before 2010 is out. The new Windows offering will present users with yet another super-capable handheld option - and it’s only going to get bigger.

Of course, email on the move simply presents yet another way to use email marketing to communicate effectively and efficiently with your target market. So it’s unquestionably a good thing.

But next time you’re crafting a campaign that will spring into life on iPhones, Androids and as yet unimagined super devices, make sure you don’t forget the importance of the element that has been around from day one of email - the subject line.

We sent an email marketing flyer for Lancaster Cambridge Aston Martin last week which resulted in an immediate sale of a brand new DBS, continuing the fantastic performance for this client.

Talking figures, the cost of the mailing was just £212, and the Aston Martin DBS retails at around £149,000.

It’s another example of how effective our email marketing can be - delivering the phenomenal ROI that we talk so much about. As well as this, it’s a neat illustration of how continuing business marketing through the current economic downturn really does produce results, something else that we’ve mentioned recently.

We’ve revamped our in-house email marketing system in the last few months to incorporate some exciting new features and introduce a new presentation interface. The new system, which is currently going through its final test sessions, will supercede our EDM for Business platform when it launches later this month.

Throughout the last eight years the Greenmedia system has provided email marketing to some of the biggest names in various sectors on a global scale, with phenomenal results across the board. We’ve built up an email marketing client list that currently includes the likes of Aston Martin, Audi, Porsche and numerous other prestigious marques - all of which have been acquired due to the continued strong performance of the system. We thought the time was right to take it to the next level, so, that’s exactly what we’ve done.

We initially created the system because we couldn’t find anything out there that provided all of the email marketing features we wanted to offer our clients. In building from scratch in-house with our own development team, we were able to produce a system that offered the latest features in a single, scaleable package. In the eight years that have passed since version 1.0 went live, there have been countless additions and amends, but it is still the case that nothing else quite like it exists in terms of mass email marketing packages. We firmly believe that Greenmedia’s email marketing offers a superior service, and our experience in the area is second to none.

The revamped version marks the biggest change to the system to date, and we’re sure that it’ll provide the platform for even more email marketing success when it goes live soon.