Also, the higher the multiple, the more that any increase in revenue will boost the final value of the deal.
Should be obvious, but it's still educational to look at some sample figures.
A $25,000 a year site sold at 4x revenue would net $100,000
The same site sold at 6x revenue... $150,000
The same site sold at 8x revenue... $200,000
But then you work hard and double the annual revenue from the site. That extra $25,000 a year could be worth $100,000 or $200,000 in your pocket at sales time depending on where the multiple lies!