While your company page on these review sites doesn't have to be as robust as your website, you should strive to make it as informative as possible.
Make sure the company profile, benefits, and salary information has the most updated information. You don't want a prospective employee to get excited over a benefit or perk that no longer exists. It's also important to make sure that the job openings are constantly updated.
Beyond the basic profile information, try to offer more value to job seekers, or anyone else researching the company. This could include snapshots about a company initiative, the company culture, or a brief employee or manager profile, to name a few ideas. It's also a nice touch to incorporate some photos and a video.
All of these efforts show that employers are engaged with these pages, which reflects well on the company.