They invest in their employees and reward certification achievement with cash bonuses. You can even earn bonuses for coming to work every day and maintaining a "billable" status. Promotions are not difficult to achieve if you are motivated.
Cons
As a consulting firm, they maintain a small "bench" of employees. Losing a major client can lead to lay-offs, which is what happened in my case.
Lots of other geeks to talk to and interact with
Decent benefits; you gain a third week of vacation just by being there for 2 years
Open atmosphere
Ping pong table
Cons
Low-ish pay
Some people like to complain, which brings the overall fun atmosphere down a bit
They aren't always able to get you onto projects that use your skillset.
They're not very good at reading the market (hiring before a drop; downsizing before a boom)