HA HA!!! Go figure!! I go to a park everyday that has 8 Pokestops, 4 of which are no more than 20 yards apart, in a square. I can sit right in the middle, put out a lure and catch a ton and garner all the extras from each stop. Have had to delete several items over and over to make room. So, I go today, sit in the general area with a lure going and catch a lot but no Ditto. I finally leave after nearly 2 hours and run some errands leaving the game on in the car. I stop at a few parks and pick up for goodies and pokemon. A few eggs hatched during this time.
Now, I head home, game still on and I pull up in front of my house. A Rattata shows up. I capture it and it turns into my second Ditto!!!!! I was like WTF!! Right in front of my house!! So now I found 2 in the past 8 hrs....
Been playing the game since mid July. Not real steady but enough to get to level 28. Of that, one level was attained by using Pokefarmer since I had only started using it last week for a couple hours each day until it went down.