Companies that specialize in memory cards have had to adapt or die. The market for memory cards has shrunk a fair bit over the past few years as many consumers use mobile devices for video and picture taking. Many wireless handset manufacturers do not implement removeable or expandable storage in their products as they'd rather charge you a huge premium for a device with more storage.
In the past, MicroSD cards were really limited in capacity as well as performance, so they only worked for certain mainstream applications. MicroSD storage has dramatically improved over the past few years and even the mainstream unit from Silicon Power is a bit of a force to be reckoned with. It's not a gale force, but it is a pretty strong contender. Make sure you read more to find out how it holds up.