What's to say I don't go into a casino, sit at a roulette table and wait for 7 reds in a row. On the 8th spin I put $10 on black, if I win repeat process again, if I lose put $20 on black, and so on until I win.

This way you eliminate the chance of having a long dry run. Sure it's a 49% chance each time that you get black after the 7th red HOWEVER it's even more unlikely that the streak of reds continues.

Tell me why this is flawed and why I can't make $1000s over the course of a couple of days.