Interesting. This has some feature overlap with Bookmark OS which I use daily. How does it let you select what info you want to scrape? What if the underlying structure that is being scraped changes over time?
By default does it use a combination of microdata, metadata and common HTML structures to find information. If nothing gets found that way, people can use a custom build in tool which makes selecting the information very easy.
If the structure changes, it does not yet get detected automatically. Rather does the first person which sees that information is not there, would have to load the parser and fix the parts that changed. Normally does not take more than a few minutes.