Make your call to action call some action
Don’t put your call to action on an image when emailing your customers. Most people won’t see it. If an action is required, mention it in the subject – or at least in the first paragraph. (This applies to not only mass email but also to private messaging.) The case in point:

Look at it again, this time with images displayed:

It is quite telling that I had already deleted this email but happened to see on Twitter someone mentioning something about agreeing to something related to Delicious. So I went back and noticed this.
Always test your email in most popular clients. Don’t focus on visual perfection – as it is impossible today – but usability.
Trackbacks/pingbacks (1)
#196: Paljon onnea meille, paljon onnea vaan | PuhujainKulma - viikottainen paneelikeskustelupodcast teknologiasta wrote (#):
[...] Muuttoviikot. Google helpottaa Google Videoiden siirtämistä YouTubeen. Yahoo kauppasi Deliciousin ex-tuubeille, käyttäjien pitää hyväksyä kirjanmerkkien siirto. [...]