Number one on that list is trust. How can I trust putting 10 BTC(a decent sum of money) into CoinLenders if the website looks like it was built in 15 minutes? The choice is not rational or thought out, its automatic.
You shouldnt decide whether you trust someone enough to trade with them/lend to them based on the design of their website.
You really shouldn't, but psychologically we do.
It happens in movies all the time--the protagonist refuses help from a scraggly, "scary" looking man, and goes with the young charmer. Who turns out to be a con artist or ax murderer. And scraggly man comes to the rescue!
Of course you can choose to override your instincts and not be swayed by looks. But most people don't because they've never thought about it.
Craigslist makes money and looks horrible. Also, this article (will update with link when I can find it again) says that the reason scammy websites work so well is because people are more willing to pay a person if the website doesn't look so professionally done. A huge 25 page wall of text with different color fonts to show emphasis shows a personal side and frequently increases sales because it takes the people out of "dealing with a slick company" mode and puts them into "dealing with guy down the street" mode.
With all that said, coinlenders is designed fine, does what it needs to do, and gets out of the way. I'd like to see some things changed, like the ability to hit "enter" after plugging in the CAPTCHA instead of clicking the button, and a way to see the interest payments on the CD instead of just the lump sum amount it's currently valued at, but overall I'm happy. Don't spend too much time designing, I've watched too many people fall into that trap and lose their shirts (and houses, and sometimes families).
