Doing a job spam doesn't give you DNs, they give you ECs. Getting free dns; Jobs. Signing up to ATA/Facebook acc. Gives you 1 DN
You get doc notes doing jobs but they are very rare. I spent a whole month doing jobs one time. I got about 45-50 ec's and only one time I received the "You found one (1) Doctor's Note" message after successfully doing a job. So they are very rare.