In recent years, funders have increased their support for early sharing of biomedical research through the use of preprints. For most, such as the COAlitionS group of funders (ASAPbio 2019) and the Gates foundation, this takes the form of active encouragement, while for others, it is mandated. But despite these motivations, few authors are routinely depositing their work as a preprint before submitting to a journal. Some journals have started offering authors the option of posting their work early at the point at which it is submitted for review. These include PLOS, who offer a link to BiorXiv, the Cell journals, who offer SSRN posting through ‘Sneak Peak’, and Nature Communications, who offer posting to any preprint and a link from the journal page called ‘Under Consideration’. Uptake has ranged from 3% for the Nature pilot, to 18% for PLOS (The Official Plos Blog 2018). In order to encourage more researchers to post their work early, we have been offering authors who submit to BMC Series titles the opportunity to post their work as a preprint on Research Square, a new platform that lets authors share and improve their research. To encourage participation, authors are offered a greater amount of control and transparency over the peer review process if they opt in. First, they are given a detailed peer review timeline which updates in real time every time an event occurs on their manuscript (reviewer invited, reviewer accepts etc). Second, they are encouraged to share their preprint with colleagues, who are able to post comments on the paper. These comments are sent to the editor when they are making their decision. Third, authors can suggest potential peer reviewers, recommendations which are also passed onto the editor to vet and invite. Together, these incentives have had a positive impact on authors choosing to post a preprint. Among the journals that offer this service, the average opt-in rate is 40%. This translates to over 3,000 manuscripts (as of July 2019) that have been posted to Research Square since the launch of the service in October 2018. In this talk I will demonstrate the functionality of Research Square, and provide demographic and discipline data on which areas are most and least likely to post.