Is SlideShare about strategy or execution? "It's about both," answers Rashmi Sinha, cofounder of the presentation-sharing Web site. It surprises her how important execution is to the process. In Silicon Valley, she explains, there are a lot of smart people with good ideas who aren't persistent enough to make their vision come alive. CTO Jonathan Boutelle chimes in that one of the biggest engineering challenges to execute was the raw scaling of the site to handle nearly 25 million monthly visitors. Returning to the original question, he adds that good execution should drive strategy.