More reaction from Alan & Bobby is available in Hammers Vision - to enter click here.
"It's always a difficult decision to lose a great player but in the cold light of day we knew all the facts - and the fact is, he wouldn't sign a new contract for us," says Alan.
"I rang him last night and got a feel for where he was at - and that made my decision.
"On numerous occasions he had been asked to come in and he made it very clear - well, not so much him, but his agency - made it clear they were not prepared to do a deal.
"If we let his contract run until the summer we might have got a lesser figure and there is a six game suspension hanging over his head if he got sent off again.
"With us getting £7m plus Zamora I think it makes sound sense and I am hoping that we have got a player who has been a bit aggrieved about what has happened at Spurs in terms of his chances at there - and wants to prove a few people wrong.
"That is the sort of players I want, people who are hungry to play for West Ham and I feel that in Bobby we have someone that shows that - and I hope he gets the goals we want.
"I don't think he has had two games back to back at Spurs and I think any young striker going to a big club needs a run - and he will get it here.
"He is a West Ham fanatic and I think he would have walked here if he had had the chance - I think he will fit into our team and I feel he balances us up.
"He comes into some great competition - Brian Deane was fantastic on Saturday with Conners - and we have got strikers beyond that, Neil Mellor being one of them.
"Although the emotion of initially will be one of disappointment with the children who come to this ground with the name of Defoe on their backs, I want them to have a new hero soon, and it will be one of the new guys - hopefully Bobby Zamora.
"I think he offers us an adequate replacement, but the £7m indicates exactly where Jermain is and where Bobby is at the moment - so he has got a bit of catching up to do.
"Whether he will ever reach the valuation Jermain has gone for today only time will tell - but in terms of the deal for us it secures the immediate future of this club, regardless of promotion.
"Although that has been said before we still have a massive wage bill for this division and we can't sustain that unless we get promoted.
"You have to face facts and this is where we are at; people might say we have sold a Premier League player and bought one that is not a Premier League player but maybe we have got three or four players at the club who are going to become Premiership players, grow here and bond for us - that is what we need.
"I do feel Jermain's red cards were harsh but that doesn't alter the fact that the next one would be a six match ban - that is a fact, and my God, if we had had that near the end people would have said why didn't we do something.
"Ultimately he would have had to have trained with us knowing this deal could have happened and that is an issue too."
Although the Premiership transfer window is over Alan can still bring in players from that division and he concludes:
"I am looking to acquire players and I think one or two more will come."