It is a reasonably common occurrence with some bikes, but others have never had it. Common things to check include tight, clean connections at the battery, clean relays, heavier duty battery cables, clean contacts on starter button, replace the starter motor with heavier duty one from a Toyota, or stronger battery.
I have tried most of those things over the last 6 years but the problem never went away. However, I developed a problem in the fuse box where the large 30 amp fuse blew and then became intermittent. I noticed that one of the slots that the fuse goes into was wider than the other one. I then added a layer of solder to one of the legs on the fuse to widen it and then put it back in. I have never had a problem with the "click" response since.