I can talk about successful crowdfunded products, including products made by companies.
To give one example to start with, Formlabs has used crowdfunding to help generate money to manufacture their 3D printers:
>"How does the crowd determine the difference between your type 1 and your type 2 companies?"
I'd suggest it comes down to experience. With experience in crowdfunding you can spot the campaigns that are likely to succeed, and which ones are likely to fail. The main problem I see is when campaigns are too ambitious based on the background of the people involved. For example, high volume manufacturing in China without prior experience of working with Chinese manufacturing companies.
This probably helped give them some runway to put together a series A. However they still raised an additional 50MUSD.
So, I don't think they're a great example of a company bootstrapping from crowdfunding. It's more of a traditional play, with some validation (and some runway) from crowdfunding.