On Facebook at https://www.facebook.com/AncestryUK?sk=app_209066239161560
"Every family has its own war heroes. You can remember yours by leaving a tribute on our Remembrance Wall. Every time someone leaves a message, we’ll donate another £1 to the Royal British Legion, up to our target of £10,000."
Also information about Ancestry WW1 records free 10th-13th November.