Earlier on Friday, Schiller told a packed courtroom that Apple's strategy in maintaining its market momentum is to "make the product the biggest and clearest thing in advertising."
The 15-year Apple veteran told the jury the company has spent about $647 million on advertising for the iPhone, launched in 2007, and over $457 million for the two-year-old iPad.
Schiller said Samsung's copying of Apple's designs has hurt its sales and disrupted its marketing.
"I was pretty shocked at the appearance of the Galaxy S phone and the extent it appeared to copy Apple products," he told the jury, adding that he was even more shocked when he saw the Galaxy tab. "I thought they've done it again, they're just going to copy our whole product line."
Justin Denison, chief strategy officer for Samsung Telecommunications America, took the stand after Forstall, stressing that the world's largest technology company by sales was also no slouch when it came to design and marketing.
Denison told the court Samsung spent $1 billion on US product marketing in 2011 and employs over 1,200 designers.
Before Schiller took the stand, U.S. District Judge Lucy Koh rejected Apple's request for severe sanctions against Samsung over the conduct of one of the Korean firm's attorneys, though she said such conduct risked tainting the jury.
A Samsung statement this week contained links to documents Koh ruled could not be admitted at trial. Attorney John Quinn, of Quinn Emanuel Urquhart & Sullivan, acknowledged he authorized the statement but said it was not designed to sway the jury.
Apple had asked Koh to punish Samsung by ruling that Apple's phone design patents were valid, and had been infringed. Koh rejected that request but said there may be a post-trial investigation.
"I will not let any theatrics or any sideshows distract us from what we are here to do," Koh said.
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