Eh.
I think I'm pretty good at my job. For the most part, I've liked my co-workers (and met two of my best friends through the business).
What I don't like about it is:
1) Every ad agency is the same. I've worked at four big ones so far since college. They'll tell you that they're all different, but they're not. They'll tell you that they have "unique proprietary systems" for "identifying the target market" and "focusing on the people who really use the product" so that we can "think outside the box" and "incentivize consumers" with "outstanding creative product" and "targeted communications plans". Whatever. I've heard it and I'm not buying it.
2) All clients are the same. Some of them are nice. Some are jerks. But, business-wise, they're all the same. They're all afraid to take risks. They're afraid of doing something that hasn't been done before, but then they penalize you because you're not being creative in your thinking. They have all of these historical models to help them predict the effect of advertising on their sales, but since the models are based on "historical data", they can't account for anything new and different you might want to do. "Doing your job" as far as a client is concerned usually just means, "How do I keep the guy above me in the chain of command off my back?", not "How do I empower the ad agency to help sell more of my product?"
3) Management at ad agencies is, by and large, really bad. There's rampant cases of "face time" (managers thinking that just because you're at your desk that you must be working, and consequently if you're not at your desk, you must be slacking off). I've been pretty well taken care of, I guess, but just like any job, you witness things happening and say to yourself, "How can that be happening?"
4) Most managers at ad agencies are far too willing to just give up and do exactly what the client wants without fighting. They are paying me for my expertise, but when it comes down to it, they don't want my knowledge and expertise. They want me to do what they tell me to do.
5) Training has gone the way of the dodo bird. I train my teams (well, when I had a team). My "team" now consists of me and another woman who's been in the business for about 18 months. She's great, but between the two of us, we can't get our work done on time. So, we cut corners, and really she and I are just churning out work without putting a lot of thought into it. On one hand, it's "easier" because advertising (at least, what I do) is not really hard once you know what you're doing. The hard part is the strategy, the thinking, the planning... these days, with only two of us, the client doesn't get much of that. They get spreadsheets and numbers and graphs of competitive spending. I guess that's what they want, because they're not willing to pay the agency for most staff so that I can actually do what I was hired to do.
Other than that, advertising is great! My main satisfaction these days comes from finding time to train the junior-level people so they learn things the way I learned them ("the right way") as opposed to just learning how to get stuff done. They seem to have responded well to that in the past (before they all got laid off after a client fired the agency).