The Company
I feel like Glassdoor hasn't quite defined what they want to do yet. Do they want to focus on branding? Do they want to focus on Jobs? Do they want to focus on Salaries/Data? When I was there I wasn't quite sure what the play was, and I think the company is currently struggling with the same questions. How the product is sold also poses as a risk for the company. Sales people have to sell the vision of Glassdoor using mashed up ROIs in order to get Marketing/HR/Recruiting to invest. I think this is why the sales/cs team is such a large portion of the company (about 1/3 last time I was there) and I think there needs to be some creative thinking as I don't see the large proportion of sales as scalable.
Leadership
I think Sales Leadership is lacking. Glassdoor is not ready to become a public company if the leaders of the sales org cannot carry a number they signed off on. Leadership consistently "signs off" on decisions and then doubles back on this and says they never signed off or were pressured to do so, you will hear every excuse in the book instead of them owning it. This type of leadership unfortunately has percolated to the bottom, where now Sales Reps and Sales Managers think it is okay to do this when they aren't hitting their numbers as well, this is why quotas changed 5+ times during my time there. The culture has turned into the blame game versus grit. Let's be honest, at most Saas companies in the bay area 30-40% of the sales org hits their quotas.
HR/Promotion Cycle
Glassdoor has a tight budget, don't expect to get promoted even if recruiting tells you that during your calls with them. I had 3 managers during my time and unfortunately this meant I didn't have anyone fighting to get me the salary I deserved. Don't expect anything to be given to you even if you do amazing work.