It's important to keep your SMS contact list as clean as possible, because you want your campaign to be as efficient as possible. You want to reach all your leads, but also limit your cost of bounces. There are two types of bounces: soft bounces and hard bounces.
These are fairly common, and can occur due to a number of scenarios:
- SIM card is not in the phone
- Out of network range for up to 72 hours
- Unpaid phone bills
- Traveling overseas (connected to another network)
This indicates that the phone number you are trying to reach is invalid or disconnected. These are the numbers that you want to delete from your contact list as soon as possible. Try to make it a goal to clean your mobile contact lists of hard bounces at least once every quarter. This will also help you discover inactive contacts, which you can place into re-engagement campaigns.