"you often have to go down a bunch of dead-end alleys and you're not even sure if what you're attempting is possible."
This is my biggest worry with my product. I literally spent two years going down dead-end alleys to refine my Information Flow Control System because there was nobody that I could copy from. We often hear "Ideas are worthless. It's the execution that matters." which is true but knowing what does and doesn't work is as important in my opinion.
Apple now knows you can capture video very efficiently with JPEG. People now know, if you want to build a powerful social media product, you'll have to use real names and so forth.
I can't back this up with citations as I don't remember where I read this from, but it basically said innovators are usually not the ones that benefits from their innovations. It's usually those that tweaks the innovations that benefit the most.
I guess the message is, if you do have something innovative, you should probably patent it. You might not be able to protect yourself from larger companies, but you'll certainly improve your chances of being acquired.