Pros
Quin Street is definitely a very fast paced environment. As a new technical web development intern, you have an obvious paved road to moving up the corporate ladder quickly and securing a full time web development position which would eventually lead to a technical management role. The company has a reportedly rapid growth rate and new teams are very flexible and often merged or broken up in corporate restructuring. There is plenty of opportunity for expressing creativity and working on personal business related projects. The company even provides you with some resources to write a business proposal for an idea you might have and execute it within the company.
Cons
The focus of the company is marketing and there exists a sensible lack of technical knowledge from some of the management. It is after all a marketing oriented web development environment where technical advancement and new technology is not always highest priority. Making money is highest priority, and that might lead to quickly patched fixes instead of properly designed infrastructure. There doesn't seem to be much technical knowledge transfer among the teams. Weekly, or biweekly technology presentations by various groups would probably help with that issue. Teams who use internal tools often are not aware of the internal working of these tools and so simple internal configurations or bugs would take a long time to be resolved.