Having only 30% hearing in one ear, I found I was missing a lot of the sound when using double ear phones with my iPad. This was particularly noticeable with tracks by the Beatles for some reason. In some cases the vocals were missing, in others the drums etc. I didn't want the type with robust glow-in-the-dark cables, I wasn't planning to run anywhere, just listen to my music in bed. This earbud seemd to fit the bill and was relatively cheap (though the postage did bump up the cost).
The thing looks quite flimsy, and I suspect will not last very long. But it really does combine the channels into one earpiece, and as a bonus has a volume control. Initially the bud gave me an ear ache after an hour of listening. But inserting it with minimal pressure achieved a much more comfortable fit.
Of course you lose any real stereo separation - but I didn't have much to begin with. I'm happily listening to 'Lucy in the sky with diamonds', and hearing everything with great clarity. Is it my imagination, or am I even getting some stereo from it?
Overall, very pleased. Four stars.