The Hammers look to have found themselves a bargain after Sakho - a £3.5m signing from Ligue 2 outfit Metz - netted five goals in as many games following his summer switch to Upton Park.
"From the moment I arrived I set myself targets. Personally, that was to get in the team. I knew that I was going to score goals, but I didn't think it would happen so quickly," he told the club's official website.
"I came from Ligue 2 and I was voted Player of the Year and on coming here people [there] told me that I wasn't up to playing in the Premier League.
"That motivated me to want to come here and to prove to everyone, that even having come from Ligue 2, I can still compete in the Premier League."