Zoho has launched zPost, a service that enables Zoho users to send printed invoice to customers.
The service automatically will send your invoice to customers (you need to first buy zPost credit).
Inside the envelope, your customer will find a professionally-printed invoice that will reflect well on your business. In addition, we include a payment coupon that your customer can detach and put in the included return envelop along with her payment and mail back to you – blog
A very useful service that a lot of small businesses will avail. This also helps Zoho in creating a bigger brand and increase (potential) customer touchpoints.