My digital camera (a Sony α55) stores photos on an SD card. When I want to transfer these to my computer (a mid-2010 MacBook Pro), I have two options: use the USB cable to connect the camera to the computer, or use the computer's built-in SD card reader.
The camera's SD card slot is the standard click-in, click-out (spring-loaded) mechanism. My laptop has a simple slot into which the card slides with a little more resistance than the former (the card slides only about halfway in so it can be easily removed).
I notice that the card's contacts now have some shiny marks from one or both of these card slots:
Does this type of wear threaten to significantly damage the card? Should I avoid switching the card between slots frequently, to extend its lifetime?