Unfortunately, the storage density of the prototype isn't very high. At a density of 40MB/inch², the storage density is roughly 10 percent less than that of a standard CD. Then again, a typical CD has a lifespan of only a few decades.
I know what you're thinking -- how can a small piece of glass last a few hundred million years? The quartz glass material is capable of withstanding some harsh conditions like water (tsunamis), heat (high temperature flames and heat up to 1,000 degrees Celsius for two hours), radio waves and most chemicals.Source: DailyTech
"The volume of data being created every day is exploding, but in terms of keeping it for later generations, we haven't necessarily improved since the days we inscribed things on stones," said Kazuyoshi Torii, a Hitachi researcher. "The possibility of losing information may have actually increased."