Whether you distribute for free, for a donation, or for a cost, it will be a Commercial Membership or higher. A Commercial membership is limited to distribution of 100 seats. This means that you can distribute up to 100 copies of a ODA-based application to your customers. Please note the following: both paid licenses and trial/evaluation licenses are included in the 100 seat limit.
If you are distributing more than 100, then it needs to be a Sustaining Membership.