WeVividWeVividWork out the real price per item and effective discount of buy one get one, buy two get one and similar offers.
It is 50% off in effect — you pay for one item and get two.
You pay for 2 and get 3, which is about 33% off.
Only if you need the extra items and the base price isn't inflated.
No. Everything is worked out in your browser and nothing you type is sent to a server.