First off, our Multiple Listing Service(MLS)  has strict rules about resetting DOM.  If you cancel a listing and re-list, you are required to send in a brand new listing agreement.  However, lets get real here… they only bust you if someone else sends in an email complaining about it, then you get the dreaded call from your board of realtors asking for a new contract.  As the market has slowed, more and more agents want to reset, as homes languish for 6 months and longer.    With the new CDOM(continual days on market)  function, even if you reset, you can still see the CDOM unless you take if off the market entirely for 2 months.  So the benefit has really been removed of resetting.  There are a few tech tricks that some Realtors have discovered which reprograms the system and resets both numbers back to 0 DOM and CDOM.  So just to be sure… always check the History if you are unsure if the home has been on the market recently.