First thing is demand. The old cliche of supply and demand still holds true, even in this age of t'internet. Type in web designer and you can choose from tens of thousands.
You get the ones that make serious money and rarely have to advertise, as clients arrive via word of mouth and recommendation, marketing gold dust. You then get the other end of the scale which is back bedroom hobbyists, and this is what the internet is awash with.
Once you have established there is a demand, then its down to confidence. If you're primary means of marketing is online, then make the most of the 3 seconds you've got when someone arrives on your site. That's all it takes for Joe public to make their mind up.
So ask yourself the same question. Look at your competitors which you know are doing well and work out why punters would go there instead. Do their sites pump out confidence? Using the web designer example, do they showcase examples of their work, can a non technical person clearly see any potential value?
Remember websites are simply shop windows, so if you do grab their attention, follow it up quickly with superb content and make them want to get in touch. Give them stuff, get them engaged in your site. I disagree with Kip slightly, as I reckon you can hook people, as well as give enough info to make an informed choice, but completely agree about decent copy. If you're crap at it, pay someone!
