Did you get the DittoGUI program?  It bypasses all the complexity of using the ditto commands in terminal mode, something I was not eager to delve into.

Here's how I use it, and what works for me.  After downloading a product from Renderosity or RDNA (or anywhere else for that matter, other than DAZ), you will find (usually) a zip file in your Downloads directory.  For example, I recently purchased a new character on Renderosity called Dixie by Sabby on Renderosity.  The download file is called Sabby-Dixie_140013_141177.zip.  What I have done is to create a separate directory I called DAZ Studio Files, and I move the zip file from my Downloads folder into that directory before unzipping.  

Next, double-click the zip file and it will create a new folder, usually with the same name as the zip file, minus the .zip of course.  Or, unzipping may simply produce a file called Runtime. This distinction is important to determine what to do next.

You need to know where your DAZ content library resides.  Mine is in Documents > DAZ 3D > Studio > My Library.  Inside of that, there is a directory called Runtime.  You will use DittoGUI to copy the unzipped product directory into either My Library or Runtime.  If the unzipped file folder is called Runtime, you copy it into your Runtime directory.  If the unzipped fiel folder is called by the product name, like Sabby-Dixie_140013_141177 in my example, copy it into My Library.

So, now you start DittoGUI, and you will see a small window with two boxes labelled Source and Destination.  Drag your unzipped product folder onto "Source" and the target directory (either Runtime or, in my example, My Library) onto "Destination.  Then, click the little "ditto mark" icon right below the lable dittoGUI at the top, and watch the spinning icon for a second or two while Ditto does its thing.

That's it!  Now your product content should be in the right places and will appear in your library next time you run DAZ Studio.  What I do now to clean up, is to trash the unzipped folders from my DAS Studio Files directory, and move the zip files into a subfolder I call "Installed" so they will be there for safekeeping in case I need them in the future. 

By the way, this whole process works just the same way if you are installing into a Poser library, substituting the appropriate directory names, of course.  I use both DAZ Studio and Poser Pro 2012, and this all works great for me.  

Good luck.

  ~ Russ