I think that when you fill up the pokedex (seen but not caught) you should get some kind of reward. Maybe something like a shiny charm (as in the pokemon games) to increase the chance of finding rare/shiny pokemon.
Something similar to this has been suggested. Filling the Pokedex (seen but not caught) is really easy and anyone can probable do it in a day. I think shinies should stay exclusive to the store mostly cause they wouldn't be as special if people started catching them.
