What settings on your camera are you using?
Flash is used as fill flash or main light source?
Do you use the flash in TTL mode?
Are camera and flash set to high speed sync, i.e. do you use faster shutter speeds than the regular sync speed in the 1/250s range?
Here are some answers:
1) By increasing ISO the ambient light will have more impact on the exposure, thus the flash when used in eTTL mode will have to use less output at a given distance to get the same result, or seen the other way have more reach with the same output. Same applies to aperture settings, i.e with the lens stopped down (e.g. f16) or wide open (e.g. f4).
2) The Better Beamer expands the working range of the flash by focussing the beam to a smaller spot. This will allow a flash under TTL control to use less power to light a target with the Better Beamer attachment than without it (i.e. flash zoom set to 50mm + Better Beamer vs flash zoom at 50mm and even its max setting). However, the flash (and your camera) don't "know" about the Better Beamer so the numbers shown by the flash(reflecting the max. usable range of the flash at the given setting) assume the "naked" flash. With "knowing" about the Better Beamer this number would be higher.
And the number assumes that the flash is the main light source (dark room, little other light), i.e. when using the flash as fill light its reach is longer than the number.
3) Point 1) applies also to point 2), i.e. pushing the ISO up with the Better Beamer will further increase the useful range of the flash.
4) If camera/flash are in high speed sync mode one can use much faster shutter speeds, but the working range of the flash will drop dramatically with faster shutter speeds. Still one can use a flash for fill light with 1/800s or a bit faster over ~20 -40 m (lens wide open) with the Better Beamer.
5) When using fill flash I set the camera that the shot would be 1 F stop underexposed, let the camera control flash output vie TTL, and dial in -1.3 - -1.7 flash exposure compensation. Depending on the subject and general lighting conditions (dark or light background) flash exposure compensation settings can vary widely (-2 - +1). This results most of the time in an image that doesn't look flashed. Fill flash acts mainly on the dark spots in the subject, so its effects can be very subtle.
6) If flash is the main light source the general procedure is the same, just that one should avoid shutter speeds to far above the native sync speed (best 1/250-1/320 depending on camera model). If the flash power/range under those circumstances is insufficient the only fix is to open aperture wider and/or crank up the ISO. However, results will most likely look like a flash was used.
Hope that helps
Ulli
P.S. Note that light does not decrease linear with distance. Each time you double the distance you loose 3/4 of the light.