The Let's React Newsletter is distributed to over 1000 developers every week. Subscribers are highly engaged and every issue contains quality, hand curated links and commentary. For an example of the kind of content in the newsletter see the latest issue or the list archives.
Every Let's React issue has sponsorships available in two sections, a single Sponsored Link which is featured prominently under the News section and a Jobs section towards the end of the issue. Sponsored links work well to get products and services noticed by subscribers and the Jobs section can be used to get roles in your organization noticed.