Thanks for the feedback. We do not have any immediate plans to change the call limit for the preview offering. We've seen from our data that 1K calls / month are sufficient for most developers who want to get started using the APIs. We we will certainly consider revising this in the future if there's strong demand. I encourage you to file this as a request here: https://cognitive.uservoice.com. We review user ideas and feedback there on a regular basis to improve our services. Thanks again!