Recently I watched a YouTube interview of Charlie Lee (father of Litecoin) and his opinion about carts and BTC's position with LTC on them. Since BTC transactions can run anywhere from $2 to $10 per transaction, it really doesn't make sense anymore to sell items in online shopping carts under $2000 with BTC anymore and LTC is the way to go. The max average LTC transaction fee runs around 19 cents. (You may have other fees if you don't run a full node to move the money and use a third-party API.)
So, I really think that there's going to be HUGE market change soon in the online crypto carts and LTC will be the prominent coin for most online purchases in the future. And more so than any other crypto simply because it's been around longer and you can brag, "LTC is built on pretty much the same technology that BTC was built upon."