How to write an effective Email Subject Lines

Why do you need to optimize your marketing email? Based on a survey, over 60% (or nearly 1/3) of online consumers made a purchase as a result of marketing emails. Hence the need for an effective email subject lines to attract their attention.

How to write optimal subject lines? Below are some tips:
1. Use "Alert", "News" or "Bulletin" in subject lines

2. Use "Daily" or "Weekly" in subject line. Avoid using "Monthly".

3. Use "Sale", "New" or "Video" in subject lines boost open and click-through rates. Obviously, there are a lot of readers that loves videos.

4. Be useful and ultra specific.

5. Identify yourself.

6. Be visually different.

7. Use timely topics and urgency that are top of mind.

8. Use a call-to-action (CTA) by asking a question.

9. Test your subject lines so you can repeat what works best

10. Use ALL CAPS to highlight words in the subject line. Example: Best PRICE.

12. Avoid repetitive subject line. Not many people like a recycled topic.

Apart of the subject line itself, you can also optimize the mail body content to maximized the click-through. Basically, you want to keep your email body short, attractive and to the point. Here's how to do it:
1. Clearly convey your offer and how it can benefit your readers.

2. Use images in your body content. People process images 60,000 times faster than text.

3. Use short paragraphs and bullet points. The average adult's attention span is 8 seconds.

4. Personalize content with Name, Location, Company, etc. 4 of 10 marketing emails are marked as spam because they are irrelevant.

5. Best practices for optimized Call-To-Actions (CTAs).
5.a Focus on one primary action you want your audience to take.
5.b Create a CTA with a button or link.
5.c Make sure call-to-action is prominent and visually distinctive.
5.d Keep your calls-to-action "above the fold," so they are visible without the reader having to scroll down.
5.e Use action, urgency, and friendly words in your CTA.
5.f Include multiple links and buttons throughout your email.

Over 70% of mobile purchasing decisions are influenced by promotional emails, thus the need to optimize your mail for mobile.
1. 64% of decision-makers read their email via mobile devices, namely smartphone or tablet.

2. 48% of emails are opened on mobile device.

3. 69% of mobile users delete emails that aren't optimized for mobile.

4. 89% of email marketers lose leads because their emails aren't mobile optimized.

Optimize your email for mobile. This is important as well as more than 60% of all emails are opened from a mobile device. And this trend is increasing. How to optimize your site for mobile? 
1. Increase the size of links and CTA buttons. The average size of an adult index fingers is 1.6-2 cm, which translates to 45-57 pixels on a mobile device.

2. Space links far enough from each other that there isn't any accidental clicking.

3. Reduce image size. Every 1-second delay in loading time results in an average 7% drop in conversion. Use services such as FastStone, Photo Resizer and JPEGmini to reduce your file size up to 80% while maintaining image quality.

4. Resize images by proportion of screen. Alter the style portion of the code in your email HTML editor to define image size by proportion.

Source: various sites.