When you write an email you must pay close attention to this first pieces of content. Apart from the fact that they are the ones that catch the interest of your recipients (so that they keep reading the rest of the document), there is an important consideration that is not usually taken in account by marketers. It's the fact that several e-mail clients show these two first lines to the reader without her needing to even open the e-mail!

How is this?

Well, take a look at GMail for example:

As you can see in the picture above, GMail shows the first words of the email automatically to your recipients. And notice that I've said "the first words". So, even although you have several images before the first word in the email, GMail effectively will show them in its small preview. GMail will fit in this space, the first 15 to 20 words in your email. If the recipient reads those lines and didn't get hooked-up then your message will probably end up in the trash folder.

But GMail is not the only example of this behaviour. Outlook does the same thing when "Enable automatic preview" is enabled (which is, by default), so your e-mails will look similar to these:

Outlook fits in its preview pane about 50 to 60 words, so it's even longer than GMail's. And the effect is the same.

So the conclusion is this: choose wisely the first words you enter in your e-mail so that people who read them will know exactly what it is about, and can get interested in the content.

Corolary:  If you personalize your e-mails so that the first name of your subscribers goes in these first words, you get more chances for it to be read. A tool like MAILCast and its powerful personalization features can do a good job with this kind of issues.