In Defragging: Why, How, and Whether, I warned that defragging can wear out solid state drives. Howard Meyer asked if it was safe to format flash drives and memory cards.
Regular defragging can wear out a flash drive or memory card (such as an SD card), just as it can wear out a solid state drive (SSD). They all use flash memory and the same issues apply.
But I wouldn't worry about formatting for a couple of reasons.
First, while many people defrag their hard drives on a very regular basis, formatting tends to be a rare activity.
Second, formatting a storage device doesn't usually involve overwriting everything on it. Formatting generally makes the space on the device available for new files, but the old data is still there until something else is written over it. Thus, it doesn't wear out the device too much.
Contributing Editor Lincoln Spector writes about technology and cinema. Email your tech questions to him at firstname.lastname@example.org, or post them to a community of helpful folks on the PCW Answer Line forum.