If you set conditions upon receiving it, then it aint free. Just like BOGO offers on tv--supposedly you get the 2nd item free, yet have to pay S&H for it. It's not free if you have to pay ANYTHING for it. Same thing applies to you putting conditions on the free gift you're giving away. If you say, ok this is free but you gotta do x y and z first to get it, then it isnt free.
I have a free car for you. I am giving it to you out of my good grace you did nothing to earn.
Want that free car? Then do the work of coming here and getting it. Does your work in coming here and getting the car mean you are earning it? If so how?