Not all that useful for consumers. At this time, as least. The advantage of DNA is that it's fairly dense (human DNA in each nuclear is 3 billion base pairs * 2 bits per base ~= 6 Gbit of information in roughly 3 μm^3). It's less dense than the IBM method described by Problem Factory, but it has the advantage that copying DNA is a lot easier than reading and recreating the patterns made by a sheet of copper atoms.

When creating ustom DNA because a less a cumbersome process, it could be a cheap and space-effective way to do cold storage (both literally and figuratively).

Also, it'd be a quite sneaky way to transfer data. Spray some DNA on someone's jacket, go through all the security measures and afterwards, swab the jacket, clone and sequence and bob's your uncle.