I've had two full-time jobs in my career. Initially I thought they were very similar and, to a degree, they are. Both positions have allowed me a lot of autonomy and freedom to learn, execute, fail, succeed, and grow. However, I'm finding that as similar as the jobs may look at times, they are painfully different.
Just because email marketing was effective the way I did it in one position doesn't mean that same formula will work in the other role. Driving leads one way worked well for one company, but not so much for the other in a much more niche market.
Through all of this, the most powerful thing I'm discovering is to never stop learning. Accept failure as being one step closer towards a more powerful solution. Plan, execute, fail (or succeed), and try again to see if you can't uncover something better.