really it depends on the niche. but i think for most the average ranges 1-3%. 5% is pretty good in my opinion. above 10% is great but this could also risk getting you banned by google. crappy ctr is usually below 1%. and like i said the ctr can really depend on your niche. ex: people on a bad credit website will be more likely to click on a credit repair ad than people on a fishing website will be likely to click on an ad about boats or something...get what i mean?