Every single order you make is a potential CD/Raid/Bust waiting to happen. It's easy to grow over-confident as a buyer and assume they won't raid you for that half-oz of bud, 5 strip, .5g of powder or whatever the hell you think a personal amount is. But every single one of us has the potential to be raided every single time they order. When they do, you will probably not have time to smash your computer, burn the house down, or do anything else to destroy the evidence. So why take the risk that they'll find additional incriminating evidence on your computer? That "plausible deniability" defense you repeat in your head whenever your pack is running late won't help you one bit when they find evidence of you visiting this sub, a DNM, or anything else that points to your interest in drugs. And if you're not using an amnesic OS like TAILS, they WILL find the evidence they need to fuck you up. Don't give them the satisfaction.
https://www.reddit.com/r/DarkNetMarkets/comments/3tiv4l/how_fcked_am_i/
https://www.reddit.com/r/DarkNetMarkets/comments/3thtx7/worried_about_cd/
https://www.reddit.com/r/DarkNetMarkets/comments/3tgu4d/possible_cd/
https://www.reddit.com/r/DarkNetMarkets/comments/3x07kn/search_warrant/
https://www.reddit.com/r/DarkNetMarkets/comments/3fyt66/got_cded_today/
https://www.reddit.com/r/DarkNetMarkets/comments/3upar2/controlled_delivery_update/
it obviously can't hurt, but it is still very unlikely for anything to come of personal size purchases. They would look pretty bad raiding someones house and finding the 1/8th of tree he bought on the DNMs and his little bong... not worth it to them