We will help you promoting your package but here are some more things to keep in mind.
If you hear of an use case of your package, please encourage its author to post the link to our discussion forum in the Use Cases category, for a tweet from rOpenSci and possible inclusion in the rOpenSci biweekly newsletter. We also recommend you to add a link to the use case in a “use cases in the wild” section of your README.
When you release a new version of your package or release it to CRAN for the first time,
Make a pull request to R Weekly with a line about the release under the “New Releases” section (or “New Packages” for the first GitHub/CRAN release).
Tweet about it using the “#rstats” hashtag and tag rOpenSci! This might help with contributor/user engagement. Example.
Consider submitting a short post about the release to rOpenSci tech notes. Contact rOpenSci Community Manager, (e.g. via Slack or email@example.com). Refer to the guidelines about contributing a blog post).
If you choose to market your package by giving a talk about it at a meetup or conference (excellent idea!) read this article of Jenny Bryan’s and Mara Averick’s.