You can spend all the money you want on advertising but in the end, advertising just causes awareness and not action.
It comes down to having a quality product. If you’re videos are as good as you say they are then word of mouth will spread it faster than any advertising could ever do.
Think about the double rainbow guy. Jimmy Kimmel tweeted about him and suddenly his video exploded. People found it genuinely funny and shared it more and more. If it was lame, Jimmy could have tweeted it and it may have spiked in views for a day or two but ultimately it would have been swept away with the winds of ADD.
The double rainbow guy ended up with a deal to make a commercial with Microsoft.