1) Litecoin is not in competition with Bitcoin. It has a different mining algorithm, value proposition, branding and purpose that sets it a part from Bitcoin. In fact, Litecoin's easier use as a payment system acts as a compliment to Bitcoin's store of value proponent.
2) Litecoin has 4x as many coins as Bitcoin. You may think this is a bad thing because they are not as rare. But it keeps Litecoin more affordable. Often people want to invest but they see Bitcoin being too expensive so Litecoin is aimed as a “lighter’ alternative.
3) Litecoin transactions are 4x faster than Bitcoin. It takes Bitcoin 10 minutes to generate a new block of coins, whereas it only takes Litecoin 2.5 minutes. The faster block time of litecoin makes it faster and reduces the risk of double spending attacks.
4) Fast well established network. Since scrypt is memory intensive it is known to be approximately 1000 times slower hardware wise in comparison to SHA256. The fact is for most of Litecoin’s history the hashrate has been relatively high and secure.
5) Fully supported by GoCoin a growing merchant payment processor used by thousands of merchants, as well as other processors such as coinpayments, Asmoney, Alfacoins and Coinify.
6) Liquidity. You can sell thousands and not crash the market. Maintains value. Look at the chart here indicating volume in the last 24 hours relative to other coins — in fact volume has remained high month after month for years. The speed, liquidity and value of Litecoin is useful to traders seeking arbitrage opportunities between exchanges.
7) Use of Lightning Network as a method of increasing transactional capacity.
8) The possibility of utilizing sidechains for smart contracts without the possibility of corrupting the original non-turing complete blockchain.