Ball seats comprising at least one sealing material facilitate restricting fluid flow through the ball seat when a plug, such as a ball, is landed on the seat. The plug is forced into the sealing material causing the sealing material to be deformed and to at least partially deform to a shape reciprocal to the shape of the plug, thereby reducing leakage around the plug and through the seat. In one particular embodiment, the ball seat is an extrudable ball seat. Suitable sealing materials include polymers and elastomers.
