I started with the product, to tell people what I am selling. By doing this I am attracting my potential client base. I am sorry, but I can not agree with your method. Basically, you are saying find the clients, get the website up and running( this is now an expense); lastly, get the product. This is the "amazon" method. Customers first, Profit Later. The question I am asking is, what if the product doesn't sell, there is no interest in it. I have just wasted my time and money by setting this up, hoping my product would sell.. My method is simple. By offering the product I am seeing the interest in that product. By doing this I can then start my website, and since I know that I will have a client base. My products will sell.
It's no so much finding clients, as in people who are ready to buy. It's more a case of discovering if there is actually an online market for your products. Using musical instraments as an example...
1)Start with the broad term "musical instraments". Do the relevant keyword research. I bet you will find that very few people are searching for the term "musical instraments" and even those that do are doing research rather than looking to buy something.
Buying terms will be things like "Best prices for practice amplifiers" or "buy a trombone online" (just thumb sucking here - you will need to do the research)
2) Find terms with more than plus minus 100 searches per day and less than 50 000 competing pages.
3) Register and exact match domain. If the term you found in step 2 was "Electric guitars delivered overnight", get
www.electricguitarsdeliveredovernight.com (or .co.za), buying an expired domain that already has some Page Rank and authority is often money well spent because it will give you a huge boost straight out of the gate
4) Put up a simple site with just a few pages of quality relevant content (just a free WordPress install is good enough) - you WILL start getting traffic for your chosen search terms.
5) Post a short questionaire or poll. Ask people what they want? What problems they are having? How can you best serve them? Offer a discount or something special when you open. Collect names and email addresses.
6) No responses = no interest. Abandon the project. You have only lost R50 on a domain name. Try again with something else.
7) If there is interest, NOW invest some money, develop a proper site, buy stock etc. The email list you built in step 5 will provide an innitial rush of sales. As the site grows, so will your search engine traffic and sales will grow accordingly.
8) Go back to step 1. Pick another term. Wash rinse repeat. Build multiple streams of income.
You don't have the money of amazon or kalahari to invest in advertising and building your own brand. Leverage the power of the search engines to discover exacly what people are looking for and then supply them accoringly.