Subject Line Testing - The key to successful open rates

After spending hours creating the perfect content, design and offer for an email broadcast many people tend to overlook one of the most important parts of their entire CRM email campaign - a great subject line! Due to the constraints of some mailbox providers the maximum subject line should be no more than 50 characters, Airship partner Return Path recently ran some research showing that email open rates were 12.5% higher for subject lines under this limit.Remember you are competing with dozens of other subject lines in the audience's inbox so keep it short and engaging!

What is Subject Line Testing?

In order to achieve higher open rates we recommend to clients that they should test their subject lines prior to sending the broadcast. Our CRM console offers the opportunity to test five different subject lines for their effectiveness. This is sent to a maximum of 50% of the most engaged people on your email broadcast list; you can define the split and the amount of time (a minimum of one hour) to wait for the result. Following the test, our algorithm then selects the most engaging subject line looking at opens AND clicks, and automatically uses it on the rest of the send.

Subject lines

What does Subject Line Testing achieve?

Overall our clients see an uplift in email open rates of around 4% when subject line testing, however a B2C client saw an amazing jump in a period of 9 months where subject line testing resulted in a 15% uplift in email open rates.

How do you create engaging Subject Lines?

So how do you get your customers interested enough with your subject line so that they open and most importantly of all interact with your email broadcast? The key points are to remember that your subject line is the first thing that customers see in their inboxes – this content is all that they use to make the snap judgement of whether they're going to investigate further or simply delete, archive...or worse still, unsubscribe from your email.Keep it short, sharp and to the point – many customers will simply get bored if your subject line has no real point to it. Many email service providers (ESP's) will have algorithms that look at the subject line in relation to the content of the ensure that your email subject line, plain text header and email content all follow the same content direction. Also remember that different ESP's have different character limits for subject lines - so make sure that the most important part of your subject line isn’t cut off from the inbox preview - a 50 character limit helps with this.Alongside being concise and relevant, here are a few more ideas around how best to grab the attention of your customers from what could be a very cluttered inbox.Personalisation:By making your subject line personal your customers feel more like you are talking to them directly. They are more likely to open your email broadcast to see what they believe you are offering directly to them. Personalisation could be something as simple as referencing a customer’s name, gender, age, birth month and many other pieces of information...helping to make the customer feel like the content is personalised for them individually.For example, we recently launched a new menu with a competition which had a winning subject line of: Feeling Lucky [Customer First Name]?Teaser:A ‘teaser’ style subject line is another way of encouraging customers to investigate further into the email broadcast they have been sent. One of the best ways to construct a ‘teaser’ style subject line is to hint at an offer/event/detail held within the email broadcast that the customer would be interested in receiving. Be aware however that this style of subject line may not encourage all customers to interact if once reading the subject line they feel the offer/event is not something they are interesting in attending/receiving.Relevance:Utilising stored information from the customers CRM record, make the subject line mimic a recent interaction. For example ‘How was your recent visit [Customer First Name]See how you can segment your event data and link to Airship's automated CRM console here.Question:Want to encourage your customers to get involved, give feedback or just let you know what they are up to? Then opening your subject line with a question could work extremely well to open that dialogue. Remember to construct your subject line so that it encourages a number or responses rather than a limited one. For example “What’s your favourite cocktail from our new menu?” encourages a greater variety of responses than “Have you tried our new cocktail?”.Variety:Ensure you have different options to test for each broadcast, this may take slightly longer to write but you have the potential to double your open rates.So, however you decide on your subject line be sure to use those precious few characters to really grab the attention of your customers and draw them into what you are promoting. Make sure you test your options in order to achieve the highest open rates. The more special you make your customer feel the more chance you have of encouraging them to respond, buy, book or simply read.