Sellers can negatively impact this by - Insisting on too high an asking price. Restricting availability for showings. Not maintaining the property in the best possible condition for showings. Given enough time all houses sell. Prices in general rise to where the asking price is correct for the current market.
More buyers come onto the scene thus changing the market.
Time costs money. There is a cost per time associated with not selling Utility costs Insurance costs Maintenance costs Mortgage costs. Loss of earnings from tied up capital. I do not offer cut-price service. Continuously analyze current price trends.