The number of contacts you can add to a media list depends on your pricing plans. You can always remove existing contacts to make room for new ones when necessary. Here is the list size restriction as of October 2018:
Plan name | Number of contacts per list |
Free | 100 |
Standard | 1000 |
Professional | 5000 |
For the latest information, please check the pricing page: https://anewstip.com/plans/