It is like any business.
You need to make a good product, and get it to enough people and sell it at a profit. Like most things in life, and in business, there are pluses and minuses involved.
On the good side, the internet has provided a great and economical way to reach new markets, advertise, develop new sales channels, and reduce costs.
But it also has done that for all of your competitors, so that makes entry into the market trickier. You need to understand what the internet brings to the table and how to economically benefit from it. The vast majority do not know how to effectively do that. Furthermore, it is taking more and more effort and time to deal with the internet side of things. It has gotten to the level that people work for companies doing nothing but dealing with internet issues and marketing. Having a staff guy for all things web, is not in a 1 man knife making shops budget.
On the bad side of things, the internet is loaded with landmines. If you don't have some sort of a web-presence these days, you are dead in the water. You can't even count on "Yellow Pages advertising" because the internet killed that entirely. Having a web presence means you educate yourself ( a slow process, impossible for some) or you pay someone else to do it (expensive for all, doubly expensive for those who have zero knowledge, or trust the designer to take care of it). The internet has also provided a very easy way for people to talk about your business. Great if it is positive, but for some reason, negative talk always seems to spread the fastest and the widest. A bad rep can spring up out of nowhere, and haunt you for years and years afterwards. Usually you can assume that once it hits the web, it is there, somewhere, forever.
For anyone wanting to profit from selling knives, or any small business, the bare minimum you must have up and running would be:
A Website - Showing your work, models available, contact info, and dealers if you have them.
Email marketing - At least 1 mailing every 2 months, bare minimum. Once a month is better. Once a week is the norm for most businesses.
Membership and participation in online forums like BF
Membership and participation in social media sites like Facebook and Twitter.
If you are serious about being profitable, then you need to extend your reach on the web, fine tuning your approaches, and giving people more and more reason to search you out. Again starting with your website, you need to do SEO (Search engine optimization) and keep doing it. It is a constantly moving target. Provide CONTENT for your customers. Give them a reason to come back to you, and keep coming back. Providing technical or historical information about knives, steels, knife makers, or repairs and servicing would be a good place to start.
So yeah. It is just like any other business.