StudyBlue - the eighth app of Christmas

I don't know what to make of StudyBlue. My initial impressions are that most apps feel a lot more subtle about trying to sell you the upgraded version. StudyBlue is making me feel like I can't access anything useful without paying from the word go. This is because I am browsing around trying to figure out how this thing works.
I give up and start making some cards as I guess I was expected to do first. It wants me to suggest a term, so I pick 'database', and then StudyBlue shows me how other people have defined database on their cards. Suddenly this is fascinating! Quite a lot of answers are fairly accurate, but some aren't, which is a bit worrying.
Next I try 'academic journal' - again levels of granularity in the responses are quite varied.
So I decide to be brave and try 'librarian', who is apparently a 'person who can help you find books or another source of information'...well, that's not so bad I suppose!
Ok, my library obsession aside, this is starting to make some more sense to me. I can see some people have used these cards to note how to reference different types of information which seems like a sensible idea.
I wonder if this could be used for some library matching card games as well.
However, for my personal learning style I don't like it at all, this is not the way I study! But this in itself is useful to contemplate, as this obviously does work well for many people, so at the very least knowing the app exists to be able to signpost people to it is pretty useful. Here are my cards so far...