Mobile marketing differs from most other forms of marketing communication in that it is often user (consumer) initiated (mobile originated, or MO) message, and requires the express consent of the consumer to receive future communications. A call delivered from a server (business) to a user (consumer) is called a mobile terminated (MT) message. This infrastructure points to a trend set by mobile marketing of consumer controlled marketing communications.[38]
Grey Routing is a term given to messages that are sent to carriers (often offshore) that have low cost interconnect agreements with other carriers. Instead of sending the messages directly to the intended carrier, some bulk SMS providers send it to an offshore carrier, which will relay the message to the intended carrier. At the cost of consistency and reliability, this roundabout way is cheaper, and these routes can disappear without notice and are slower. Many carriers don’t like this type of routing, and will often block them with filters set up in their SMSCs.

In the article cited at the beginning of this post, the author boldly claims that “a major chunk of the population is already registered with the DND.” First, there is no clear statistical research backing up this assumption. Second, in the U.S., the Do Not Call registry protects consumers from just that — unwanted calls. It’s designed to prevent telemarketers from harassing consumers. This has absolutely nothing to do with text messaging. Now, if for some reason you do find yourself receiving unwanted text messages, you can file a complaint. But, knowing the permission-based nature of this marketing method, you may never confront this issue.
In order to gain their mobile number, they will have to have a great deal of trust in you and a pre-existing relationship will help. They also need to know that what you'll be sending them via SMS message is exclusive offers, not the same offer that you give via email and social media. Be clear with your customers and use the following guidelines when introducing SMS marketing to your customers: