Marko Arnautovic says he has joined a "bigger and more ambitious club" by leaving Stoke for West Ham.
The Hammers, who have also signed Joe Hart, Pablo Zabaleta and Javier Hernandez this summer, splashed out a club-record £25m to secure the services of the Austria winger last week.
Since completing the move, Arnautovic has come in for criticism from Stoke chairman Peter Coates and midfielder Charlie Adam, with both expressing their disappointment at his decision to leave the bet365 Stadium.
But the 28-year-old is convinced he has made the right choice for his career by joining West Ham and believes Slaven Bilic has put together the "perfect team" ahead of the new Premier League season.
"To the fans I was let's say the hero and now I am zero. But that's football. The one thing I can say is, I am happy to be here and happy to play for West Ham," Arnautovic told Sky Sports News.
"Of course it was tough for me because the fans over the years were very supportive of me, but I came to a point where I wanted to see something different.
"I wanted to join West Ham because, for me, it's a bigger club and more ambitious. We can see with the signings that we've made and the players that are already at the club.
Hart: West Ham aiming high
Joe Hart believes West Ham are capable of at least a top-eight finish this season after a busy summer in the transfer market.
"I think we have a perfect team and now we have to show it on the pitch."
Arnautovic, who scored 26 goals in over 100 appearances for Stoke, also insisted he is not feeling the pressure of being West Ham's record signing and is determined to deliver for the club.
"I think I'll feel the same when I am playing, even if I came for more or less money. It's of course an honour for me to be the record transfer, but it will do nothing to me," he added.
"I have just come to this club to give my best and to show the fans that every penny was worth it for me. I want to give everything."