It depends on a few things:

• First of all, if you're looking at "living pictures" on the Lytro camera, transfer them to your computer before you give up on them. You may not see the full refocus range within a given living picture until you view it on a bigger screen.
• Next, if you're already looking at living pictures on your computer, have the pictures finished processing?
• Also, was there depth in the image to begin with? For instance, if you took a portrait of a friend standing against a wall, there will generally be no depth info at all; you must think in 3D, and then compose your picture in 3D, in order to get 3D results.
• Pictures taken with the camera's zoom slider set to different zoom levels will require different distances between the subjects in the foreground, midground, and background in order to refocus your pictures clearly.  Please make sure to follow these shooting tips for best results.
• Finally, when viewing living pictures on Lytro Web, remember that you're looking at a web-optimized version of each picture; it wouldn't be very share-friendly otherwise, but you won't get the exact experience you would on a computer: some fine control over refocus depth will typically be absent on Lytro Web compared to what you'll see in Lytro Desktop.