The world of electronics is moving further and further away from Through-Hole components and towards SMT (Surface Mount Technology) every day. Sometimes this doesn't always go well for the enthusiasts building at home, so we have to adapt.
SOIC to DIP adaptors are useful for many things:
For prototyping a circuit on a through-hole proto-board and later converting to SMT
For saving money with cheaper SMT chips
Some chips might only be available in SOIC packages
Programming SOIC microcontrollers without expensive ZIF sockets
These kinds of boards are available at websites for $1 to $3, but if you are trying to cut costs by using SMT components in the first place, you may want to make your own. If you have circuit board etching supplies handy, you can make these adaptors for 25 cents apiece.