Do you guys think it's a good idea to use a keyword that has 0 competing sites and still gets like 10-30 visitors/searches ?
It really depends what it is, it would only probably take a handful of backlinks to rank number one so why not give it a try.
usually 0 competition means the niche or keyword is not profitable. but if you can find a term/niche that has no competition and some searches, then it would be walk in the park to get it ranked. how you will monetize such site is the question. it has to be profitable or atleast worth your while
As part of a longtail strategy, it's worthwhile, i.e. if you find a hundred or so more longtails to target in the same way.
In my opinion, is would be good to give it a try. Getting around 10-30visitors/searches is quite good. If you can dominate that niche, in the long run, you could make profit from it.
Yeah I think to make it work really well you would have to find many many longtail keywords like this. Think... if you can find 10 (which I've just about found) that could easily be 10 or 30 visitors x 10. That's not shabby.