In a nutshell, mobile devices are arguably the most personal items we own and as (SMS/MMS) marketer building your phone number database in the early stages of your (SMS/MMS) campaign, you need to let subscribers know what they are opt-in for. keep your promise and send only infrequent, valuable text messages. Remember to keep delivering value through incentives and your customers will stay opted-in and very eager to receive your next text.
Once you've collected your mobile numbers, verified that you have followed all of your legal responsibilities you can start your SMS marketing campaign. I'd suggest using a 3rd party service provider to ensure that you are able to track the return on investment for your campaign, embed an unsubscribe message, and easily manage your SMS marketing database including unsubscribes.