Heads up, Prime sharers. Amazon is cracking down. Starting October 1st, the company is eliminating its Prime invite tee program.That's the one that lets people outside of your household piggyback on free shipping and Prime benefits. From now on, if you want those perks, you'll need your own membership. Amazon is offering a steep discount for that, just $14.99$139 price.There is one loophole called Amazon Family, but that only works for adults and teens living in the s ...