It may not be the case, but
it looks like a cynical ploy to get new sign ups and to get money into the accounts of people already with accounts.
I also don"t see how it fits in with the principle of "responsible gambling" which I"m sure every poker site and poker room is signed up for.
I don"t actually see a maximum daily deposit limit on Blue Square advertised - but the top prize is well over the maximum daily deposit limit for most sites I"m on which have set one. Pokerstars, for example, have a $600 daily limit and a $1500 weekly one - the winners of the 2 events will have £1300 and £1000 deposited into their Blue Square accounts in one go - how can this be considered responsible?