Whilst the character limitation on text messages will prevent you from sending a full newsletter to your customers in this format, SMS can still be used to help increase your subscribers.
Increase your newsletter sign ups by getting your customers to text a specific Keyword (e.g. NEWS) to an SMS Short Code, in order for them to subscribe. You can advertise the SMS Short Code in your promotional materials. It will then be possible to notify them via text message when newsletters are released. You could even send a hyperlink to direct them to the online version of the newsletter itself.
This will help ensure customers are always up to date with the latest news and developments within your business.