For those always wondering if you should build a list or not, consider this. Say that you write 100 articles 2 times. The first 100 point to your landing page (which converts at 40%), and the second 100 point straight to a CB sales page (or review page, blog... you know what I mean).
Let's also say that each article bring in 10 visitors per day, and your product has a $20 commission.
Ready for the comparison? At the end of month one, your landing page has gotten 30,000 visitors and 12,000 of them have joined your list. Averaging $.75 per subscriber per month (which is conservative), you'll make $9,000.
But what about those straight links? They've also gotten 30,000 visitors, and at a 1% conversion rate you'll make $6000. For those who think that Clickbank sales pages convert higher... very rarely.
Even if the page converts at 3% ($18,000), you lose all that traffic. With a landing page, you build income. As your traffic tapers off, you still have the list to market to. Not so with straight linking. After 1 month, the person with the list makes more. So put up a landing page!
Disclaimer: Yes I know that not every article that you write will bring in 10 visitors a day(depending on backlinking, the keywords themselves, and the rotation of Saturn's moons), but it made the math easy. Plus, no matter what numbers you use, you will make more money after the first month with a list. So don't focus on the numbers, focus on the concept!