We have a Unity built browser based game. We are losing players both due to the slowness of the game download and the unfamiliarity people have with downloading the Unity player. I remember hearing about some software enhancement that can speed up the downloads?
I don’t think there is anything that you can do to alleviate this issue, which is why a lot of people tend to go towards HTML5 development instead of Unity for web player games.
The first time the Unity plugin is ran and installed, additional assets are being streamed in and there’s nothing that you can do about this. After the initial install of the Unity plugin and the first time your game is ran, most of the data will now be cached and load times will be considerably lower after the first go from my experience.
All you can do is notify your customers of this, there’s no way to speed it up.