One thing that I have learned over the years is that when you're dealing with kids, consistency is key. It doesn't really matter what job chart or reward system you use. What matters is that you follow through with it consistently. You can't just create a system or plan for them and expect them to keep up with it on their own. You must be prepared to continually be the enforcer.
My "family store" keeps getting fancier and fancier. I just so loved the glass jars I had to buy more (they're only a couple bucks each at Hobby Lobby when they're on sale.) And then I went to the local specialty candy store recently and stocked up on some seriously fun candy. (Do you remember how when I started the family store I was trying not to have it be full of sugar? Ha! It's pretty much all candy now!) Gummy sharks, chocolate coins, hand-selected flavors of salt water taffy, and POP ROCKS. My kids adore Pop Rocks. I adore Pop Rocks. Admit it, you do too.
But it doesn't matter how awesome it is and how delicious the candy is. It only works as a motivator when I am consistent about it. If the kids know that I actually am going to open the family store fairly regularly (we shoot for Saturday mornings and most of the time we make it) then when I say "who wants a Badger Buck?" they come running to do my bidding. But if I'm always too tired or too busy and the family store gets pushed back and back and back then they don't care anymore.
And that's happened many times. So we try again. When I start being consistent about it again, I am always amazed and pleased at how well it works. Even when the candy is running low and the choices aren't great, they are still eager participants. It's all about consistency.