Guys, what advice would you give to your newbie self (when you were starting AM) from your current perspective? 
P.S. 1 person - 1 piece of advice
don't do seo
Start with Facebook.
If something works, scale it fast!
Love this kind of threads!
Here is mine:
In the good times when everything works well, you should work even harder! (Sometimes I still struggle with it)
don't focus on revenues, focus on margin! dont think in percentages, think in absolute numbers.
Stay focused on 1 thing (or very limited amount of things) until you master the basics, don't jump from one thing to the next!
Think and act like you are an investor in your business, not an employee.
Focus on skills, not tricks/loopholes
Don't be afraid of losing money, investing or taking calculated risks. For many people, me included, it's a barrier to spend money on traffic or other expenses ... but compare it to opening a brick and mortar business, and you'll see how cheap affiliate marketing is.
Many businesses lose money for years when they start up, have way higher running costs, and much less room for scale. Obviously there's drawbacks such as risk, changing technology etc. but it's still pretty good IMO.
I'm still a newbie, but this is a less newbie me speaking to newbie me ...