This comes up less and less frequently among my clients, and for that I am grateful. Splash pages are sort of like a preface, an introduction to the website, and you have to click through something on the splash page to get to what you want. When was the last time you read the preface or introduction in a book you were reading? Point made. If it's so unnecessary that you have an option to click to ignore it and go to what you want, it's UNNECESSARY. And anytime you frustrate your site visitor, you risk losing them. If it takes too long, or it's more complicated for them to reach the information they want, they will go somewhere else.