Cash Out Betfair?

Been a while since i was on here, relaxed a wee bit on gambling last while but back at it with the Euros. Anyway, looking for bit of info from people in the know. Anyone able to enlighten me about this new Cash Out option on Betfair?
Seen it mentioned in few betting posts but unsure how it works. I laid Czechs this evening @ 3.35. Stuck on almost €20 for a €8.50 return. However after bet was matched there was this Cash Out option. Was a figure of €19.71 with Profit/Loss in red showing €-0.27.
Anyway in simple terms, anyone able to explain this to me? And its benefit? Suppose if anyone can explain it in relation to my bet above.
Well, good luck to everyone with their Euro bets and appreciate any responses to above.
Cheers.

In that instance it means that you can cash in your bet at that particular stage and take a loss of 0.27.

Effectively, it's telling you that you can lay at slightly higher than you backed at which is pretty obvious when you think about it. For me, it's a load of bollocks. People will be pressing it by mistake or pressing it not knowing what it means. As with much of betfair's updates, it's a backward step - tinkering with shit that doesn't need tinkering with.

Cheers ODM, sounds like load of bollocks alrite, thought it was something more interesting but seems not. Appreciate the response.