As an Account Owner, you can invite an unlimited number of users.
Seenspire enables you to choose from 3 different roles.
The three roles are as follows:
1. Curator: a curator can only manage/edit existing feeds.
A Curator cannot add or create new feeds.
2. Manager: a Manager can perform the tasks of a Curator and can additionally add/create new feeds as well as connect new content sources.
3. Account owner: an Account Owner can perform all the tasks of a Manager and can additionally manage users as well as Account and Billing information.
For more information on how to invite a new user to your account, read this article.