If you’ve been following Google closely, you would notice how differently they approach a problem or need. They try to have fresh perspectives, and tend to attack their targets from different angles. Google Base is yet one of the ways Google has proved this principle. Instead of doing what everyone else has done with their listing sites, such as Craigslist and eBay, or establishment review and rating systems such as Yelp!, Google chose to go the extensible way. So with Google Base, you don’t have to limit yourself to rigid rules. You don’t have to follow a pre-existing taxonomy or classification system, but you are the one who will assign attributes and tags as you deem appropriate.

But here’s an even better deal: Google Base allows you to upload listings en masse. So if you’re a merchant with a handful of items to sell, or if you’re an artist with several works to share, you can simply batch them all into one file, and then do the upload as if it were only a single item.

Perhaps the easiest way of doing this is by using a spreadsheet application, such as Microsoft Excel, or OpenOffice Calc and saving as tab-delimited plaintext format. The trick is defining the first header row as your attribute type, and then you can go along row by row to input the appropriate attributes for the item listing (which is supposed to be at the left-most column).

Google even has suggested attribute sets in its Base FAQ.