Vantaggi
To a certain extent being a current employee makes me biased, but I will endeavor to be honest here since I am staying anonymous (though someone smart could possibly sleuth who I am). Despite being frequently recruited by bigger-name tech companies (i.e. Google) during my tenure here, I stay because something special is happening at TubeMogul. In terms of corporate success, TubeMogul hits its aggressive revenue goals, the exec team works hard and the company has a knack for making the right moves. But what keeps people here (very few leave) is much deeper than that. TubeMogul is not not the flashiest startup in ad-land, but it has a reputation for honesty and backing promises with real technology clients can see, and that matters more. In a media industry with vaporware and buzzwords and BS, we have the culture of a tech company -- transparent, and backed by engineering few if any in our space can match. This culture of transparency permeates how employees are treated, as well as into products and marketing. Another big part of the culture is something the execs call "bias for action" which I guess is a cliche now that Facebook made a similar phrase famous but is very meaningful in terms of day-to-day work-life. When I started, I was told that "you will never get judged here for making mistakes if you are getting sh*t done; what you WILL get in trouble for is inaction or dropping something." This is freeing, and it means people can DO more with fewer questions, learn faster and actually end up making better decisions in the long run. Personally, I've been pushed to grow, leading to three promotions since starting. Others have experienced similar; there are a handful here who we hired straight out of school who are now very senior or even heads of departments. In terms of perks, TubeMogul has the standard startup bells and whistles: stock options, party buses to rented venues to celebrate achievements, massage chair room, mixers, freebies, good benefits (medical/dental/vision/life with a $20 buy-in for most single folks), etc. Plus if you're in Oakland or Berkeley or its environs, there are few companies that can match the location. In short, they're killing it.
Svantaggi
Beer isn't free, but it does come from a Coke machine. Career-wise, there is a lot of responsibility and some pressure, which isn't for everyone (I actually view this as a pro but put it here for reference), and you have to be proactive to establish yourself. The only other thing I can think of is that I agree with whoever said that there are a few less-recognized folks in the middle who are maybe less outspoken about it but are truly stellar, and might be considered for more responsibility and deference rather than hiring from the outside. I bet HR will remedy that.