Alright, I was reading info at googlebase on the basics of how they work. I'm somewhat familiar with markup language used as rss for podcasts; but I'm still trying to get the feel for the whole thing.
But I have a question maybe related to varietees string.
I plan on manually creating spreadsheets, but here's the thing, I noticed some of my t-shirts are already on there (google products).
So how does that work? Can google penalize me if I start uploading my spreadsheet files and someone out there has an automated feed thingie uploading info for the same product?
How am I supposed to know?
Or I guess google spider-type software could have retrieved that on their own? Your thoughts plz.

no cafepress loads some to the cafepress marketplac but shopkeepers can load their own linking to their shop