Kerching and Win will reward you with large cash competition entries when you use their links to shop online as you normally would.
One of the easiest ways of doing this is with LottoSocial who are one of the UK's largest lottery syndicates. When you join this lottery syndicate you have the choice to easily play EuroMillions, Lotto, PowerBall, etc from just £1. By joining their existing syndicates you can increase your chances of winning a share of their possible multi-million jackpots. Their current offer is to join 5 lines for £1 and get 5 more free.
I'm not aware of many disadvantages when you join a lottery syndicate, other than having to share the prize with other syndicate players! So if your numbers win £100 you won't get a big share, but imagine if your numbers came up for a few million! Even a share of that would be handy!
They buy tickets on your behalf, manage payments and the all-important pay outs.