Must make a profit otherwise it wouldn't run at that hour, last buses would be around 11pm.
About 10 years ago Liverpool used to have night routes mostly ran Saturday night, last buses ran 3am, however they were cash fares only, seem to remember £4, no pre paid tickets were valid, i remember catching one one Saturday night, a taxi would have cost £20-£30 as i was going through the tunnel, the night buses ended up being withdrawn 2012/13.
There used to be all night bus Liverpool-Birkenhead operating every night numbered 150, that too has since been withdrawn, think similar time the rest of the night buses were withdrawn
Stagecoach have night journeys Fridays & Saturdays on the 1 Liverpool-Bromborough only, they used to run through to Chester via Ellesmere Port, but put up for withdrawal, after consultation Stagecoach cut them to Liverpool-Bromborough
The Arriva Crossriver Saturday night buses were finally axed back July 2014, they had the following -
N23 Liverpool to Liverpool via Birkenhead, Prenton, Upton, Moreton, Bidston, Birkenhead Park,
N37 Liverpool to West Kirby following the day time 437 route however didnt operate a return journey to Liverpool, rather the bus ran back empty from West Kirby. One trips extended the extra couple of minutes to Hoylake for no known reason.
N450 Liverpool to Liverpool via Birkenhead, Duke St, Gorsey Lane, Liscard, Seaview Rd, New Brighton, Rake Lane, Liscard, Gorsey Lane, Liverpool plus one trip which ran as far as Hamilton Square Station only. The N450 ran both Friday and Saturday night whereas the others didnt.
A year or 2 earlier there was also the N51 Liverpool to Spital Crossroads which again ran back empty. Following complaints from residents of Neston that they wanted it extended to serve them, Arriva said yes, nobody used it and the whole route got axed as a result.
The Arriva night buses got axed mainly over costs - they insisted on having security guards loading the buses at Queen Square for no apparant reason which must have cost a fortune, and the use of Queen Square itself made no sense as the normal cross river services don't operate from there, so not exactly making life easier for anybody looking for a bus back to Wirral! Stagecoachs Liverpool to Bromborough night bus which currently runs, picks up from the same stop the day time service does and follows the same route, allows prepaid tickets and passes and charges the usual day fare prices (or it did last time i used it) - its usually very busy when ive been on it. This is another reason Arrivas didnt work, as it was a £4 flat fare and no prepaid tickets allowed, with the exception of ENCTS blue/orange and Mersey Yellow.
On the subject of Merseyside night buses, I believe a number of late night services on weekends have been announced through December running up to Christmas as per previous years but I havn't had chance to look into it yet.
The only 24/7 bus on Merseyside is the 86A which operates from Liverpool ONE to the Airport.
EDIT
Quick look on the Merseytravel website shows no extra night buses are laid on this year, just the usual ones. They have added 2 late night trains on Fri/Sat nights throughout December leaving Liverpool Central at 0130 running limited stop to Hooton on Wirral Line and Southport on Northern.