How to install the add-on?
Install on Firefox
To install the add-on in Firefox, you have 2 ways:
1) Go to this official Firefox Addons Webpage and click Install.
2
) Download the file OneClickBestDeal.xpi, then drag and drop it in Firefox.
To change your country, go to the menu Tools>Add-ons> OneClickBestDeal and click Options.
Install on Microsoft Internet Explorer - 5 Steps
Download the OneClickBestDeal.exe and lauch it, the window under this text appear, choose your language and continue with a click on "Ok".

Follow instructions.

Choose your installation folder then press «Install » button.

Installation is done, click "Next".

Congratulations you've installed OneClickBestDeal successfully!

Note: You have to restart your browser to activate One Click Best Deal.