Proflowers

In a sponsored FarmVille link, Pro Flowers is offering 100 farm cash to those farmers who purchase fresh flowers for Mother's Day Gifts.
You must purchase online from ProFlowers.com by clicking on the FarmVille sponsored link to get the farm cash reward. The sponsored link can be found under the FarmVille loading screen. Orders placed now have guaranteed delivery for Mother's Day.

It is not a scam as this satisfied person says

"So I ordered through the “ProFlowers +100FV$ offer”
…and I got the FVC instantly, which is freakin’ awesome.”
I’m going to try another go at it and see if I get another 100 FV$ (I’ve got a mom + step mom, which explains 2 orders)".