While your equipment sits there you have others who are in the same boat looking to get into the BTC world of mining, You also have the 1s already hooked, both buying equipment, meaning your shares will get less and less, the ROI gets further away. 3 months goes to 6 months, 6 to 12..... Your now in the 2nd category and look to either reinvest the BTC you have made or spend more money to keep up.
The BTC circle of life begins!