It depends on the MLS. In our market you can cancel a listing and relist it the next day and the clock starts over. When I work with a buyer I always pull the history of a house (once they identify which house they are interested in) to see how many times it has been listed. This will not only give you how many times it has been listed but also the days on market, what the pricing was compared to now and any other information showing what has changed. They may have changed REALTORS, taken amenities out of the listing (deep freeze, washer, dryer, refrigerator, etc.) or added something (home warranty or home inspection). They could have also improved the property which should be in the remarks section (new carpeting, etc.). You cannot get a complete picture until you delve beyond the initial information pulled. After getting all that I also call the current listing agent to see what the story is (if they know the whole thing). Motivation can also change. Sometimes the first agent lists the property too high, causing it to sit, then be relisted, lowered in price or changed in another way. As our current market has been in decline, the seller could have started too high and is just chasing the market down. If they are not quick enough to move and adjust (especially in high priced homes) they might be, as they say, a day late and a dollar short. Those homes usually sell for way less than they should as they become "market worn" in the consumers eyes. That's why is not only important but IMPERATIVE that you list your home correctly from the get-go.
Hope this helps.
Trisha Lee REMAX Boone Realty, Columbia, MO