Mining Litecoin generates £0.97 profit per day (actual, real-world figures). Conclusion: not worth the effort, and certainly not the investment.
This is based on the actual figures of my mining rig, actual hash rate, actual pool fees, actual electrivity costs, and the well-regarded Litecoin Mining Calculator for extrapolating LTC/day.
GPU: R9 280X. 691Kh/s. Gross mining revenue 0.22LTC per day. My rig has been pool mining for about 14 hours and seems to be performing as per the Mining Calculator.
Current LTC price c £9.50. 0.22 LTC = £2.09 per day income.
Single GPU rig averages 370W/h without monitor. Cooperative Energy (power company) is £0.1265/KWh including 5% VAT (fuel tax). Fuel cost is £1.12 per day.
Income minus running cost is £2.09-£1.12 = £0.97 profit per day.
Given the cost of the card alone, around £270, the break-even point is around 11 months, without any other hardware or time taken into account.
Here’s where the variables come in, the what-ifs.
What if I buy another card? I think it will run at 250W and double the income. Calculations show a daily additional profit of £1.33. Break-even point 6 months 20 days.
What if LTC prices rise? They were 50% higher on my exchange while I was researching rig building. They may recover or fall lower, or sky-rocket. That’s opinion, but the current facts are above.
Mining difficulty will get harder. Maybe the increase in difficulty will offset the rising value of Litecoin.
Cryptocurrency is volitile. Governments seem to be trying to regulate it, outlaw it altogether. In the UK, mining income is taxable.
From a theoretical, intellectual, practical, and geek point of view it has been a worthwhile experience. From a money and time point of view, I wouldn’t recommend it.
CBits Tech Support 
Where it is profitable now is if YOU USE ASIC MINERS. Difficulty rose faster than people expected, but for 900 bux you can get a ASIC MINER with little power 300 watts that hashes at 6.4 MH/S which will get you almost 300LTC in a year, 3150 bux in a year most of it profit, even at the current price of 10.85 per LTC. The value of LTC should rise as BTC has done, and when that happens our profits will rise. GPU MINING is not profitable and hasnt been for awhile, the future is with ASIC miners, I bought mine from zoomhash, check it out. GD LUCK and dont give up.
Ok, first of all the reason you mine litecoins now is not for IMMEDIATE GAINS. Just like bitcoin mining when I first started it got harder, I ended up with about 50 bitcoins over a year, but the price skyrocketed to I made out. Litecoins should hit around 1/4 of the price of bitcoin, so around 100 bux or so. Even right now, if you purchase a decent ASIC miner from say zoomhash for 800 bux, mining at 7GH/s, you can recover your investment using only 150 watts or less in a bit less than 3 months and that is at the current value of litecoins. In a year you will have 200 plus litecoins depending on the rise in difficulty. Even if the price stays the same you could still cash out next year with a net profit of about 1500 bux, BUT if the value goes up to 30 bux next year, or what we supporters believe 100 bux in a year then your looking at a 30k cash out profit. SO YES litecoin mining is VERY MUCH worth it with these new ASIC miners. With Graphics cards ABSOLUTELY NOT, but with a blade ASIC around 7Gh/s, profit in 3 months, and everything after that is pure profit that you hold on to when litecoins shoot up. DONT GIVE UP, if I would have given up on BITCOINS I would have missed out one 100k of profit. GET IN WHILE YOU STILL CAN. Digital currency is going NOWHERE and regulation is for the USA only right now really, and china, but if the GOV recognizes it as currency, if EBAY, PAYPAL jump on, which its in the works, DISH NETWORK is accepting bitcoins, many places are accepting bitcoins right now and in the future, LITECOINS can be turned INTO BITCOINS, so the future IS BRIGHT for digital currency