In 2006, a Canadian research team conducted a study to try and ascertain how short a time it took for human visitors to sum up a webpage. And the results were startling!
1/20th of a second can be a killer
The team began by showing 50 millisecond glimpses (that's 1/20th second) of webpages to the participants, then had them rate the webpages in terms of their aesthetic appeal. Then they let them see the same pages for a much longer periods and had them rate the pages again. Surprisingly, the results were very close. The conclusion is shocking to us as designers (and should also impact anyone with a website as well)...
According to the results in the study, you have 1/20th second before a visitor decides your sites flies or dies in their thinking!
This makes choosing a designer with good design and layout skills so critical. Forget fancy "gadgets" on your site, even quality content doesn't matter at this point. If you site turns off a visitor, then they may not even see your content - they're hitting the back button!
Of course, they will see the page they navigated to, the hand can't move that fast, but the visitor already has an opinion of the site, and you can bet that this will color their thinking of everything on the site. They'll either be inclined t believe or inclined to disbelieve based on that initial 50ms opinion.
Are DIY websites a no-no?
Not always, but, in general I would say yes they are. And not just because it's my business. I design sites to help my clients succeed by putting their best (internet) foot forward. I'm passionate about what I do and see the pitfalls of doing a "selfie".
Most business people don't have stellar design skills - that's why they're a roofer, an accountant, a mechanic, whatever. But, just like any one of those 3 is a specialist field that we can stumble through ourselves if need be, it's much better, and safer, to have a skilled pro do it. Likewise website design. Business owners not only lack the expertise in site design and construction, they also lack the time to do it, to maintain it, and to fix it when it gets broken.
So... do what you do best, and let an experienced designer handle your unsleeping, 24/7 salesperson - your website. 1/20th second is all the time you have!
(Thanks to the original study here - http://anaandjelic.typepad.com/files/attention-web-designers-2.pdf)