Play Pick My Postcode (free)
For the past 2 months, I've been playing Pick My PostCode. It's much like the Postcode Lottery, except it's completely free. They get their money through paid advertisements. So far, I've won nothing as my postcode has yet to appear, but if you sign up, you might be lucky. My friend has won a tenner here and there. However, he still checks each day as you could win over £1,000.
If this is something you're interested in, then you can sign up here. It is an affiliate link, but the money just becomes part of a potential bonus. If you choose to sign up, then I wish you good luck and I hope you have better luck than I do.