2.5 months after the free plan was introduced, we closed it down.
There are 2 reasons:
1/ We've managed to increase our sending volume to a level that we're content with.
2/ NONE of the free users were not upgrading to the paid version --most likely because the free plan was too generous -- it had everything the paid plan had, the only difference was in the number of contacts/subscribers allowed. Even the free plan can store up to 5k contacts, which was a lot!