If you’re working with CM.com’s platform, use the Address Book to randomly divide your recipients into two marketing groups. Create two separate campaigns, one for version A and one for version B. Keep everything in the campaigns the same except for the element you want to test. Set up your message, implement the changes in version B, randomly add one of the recipient groups to campaign A and add the other to campaign B. Send your message, and wait for the results to come in.
ON-NET routing is the most popular form of messaging globally. It’s the most reliable and preferable way for telecommunications / carriers to receive messages, as the messages from the bulk SMS provider is sent to them directly. For senders that need consistency and reliability, seeking a provider that uses ON-NET routing should be the preferred option.
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.