Facts are.
If you long CFD's you are receiving stock you do not actually own and you are gearing up so you have to pay interest for that.
If you are short you are lending out stock to someone so you recieve interest
Cfd providers normally charge interest at Libor plus a margin of 3% typically
and pay you interest around Libor or less.
Also you have to pay the Divi's or receive them depending whether long or short, so if a company like BP or shell have a divi whilst you are short on the Indicies it costs quite a bit or if you are long you receive the Divi.
Re Spreadbetting.
They make the money via the spread and the fact that you roll-over they do not normally charge interest or pay it the roll-over price is calulated bearing in mind costs, interest, Divi's.
Can't reply anymore as off out for a day.
Careful with any Longs in place as I believe 12 targets from a training camp in Afgan have gone missing believed to be in UK (as quoted in news)