Firstly, thanks for your kind words. As you say, there are plenty around that are happy to talk whatever garbage it takes to make a few dollars for themselves, but we live by a simply philosophy here. We can't always tell people what they want to hear, but we can always tell them what they need to hear.
To your questions
Research, there are quite a few different facets to effective research, but initial market research is all about identifying products that offer some potential. Our Lab offers members the opportunities to check to basic information, eBay also has a good feature that I think is often overlooked and that's the Completed Listings feature.
That will give you an indication on sell through rates on products and general sale prices. Of course that's all what we call surface data, without knowing all the details about those listings, you can't draw detailed conclusions, but it all goes towards painting a picture. So research is all about drawing on as many avenues as you can to try and put a half decent picture together.
A really good tool is Terapeak, of course that is a paid service because providing that level of research is actually super expensive. People don't realize, but companies like eBay charge a LOT of money to provide research data. We pay quite a lot for the access to the data we provide through eBay, but we have to limit it so we can absorb that cost and pass on to our members as free tool.
The thing about research is having the ability to decipher it accurately as well. Some times what you can't find out about a product can tell you far more than what you can from finding data. I know that's confusing and it's something that you really only gain from experience. It's not something that can be simply taught unfortunately, but those who have been in this business for a long time will know what I mean :)
Once you get a basic feel for a product/s, test marketing is always a great idea and this is where something like drop-shipping can really shine. It allows you to list products at no great expense, play with your listings, free shipping and so on, see how different listing strategies work over a period of time. There's nothing quite like firm sales data over an extended period of time to give you accurate information to move forward with.
Things like this is why you will see me write that it's a business and running it like a business takes time to get results. Without taking the time to really narrow down and understand your market so you can fine tune everything means you are kind of shooting in the dark mostly and that's very much a hit and miss strategy.
Is there ever any guarantee that a product is going to sell, well I guess you could always sell something 50% cheaper than anyone else and lose money, that might guarantee you a sale, but it can't guarantee you money of course. So in short, there is no guarantee on ever selling a product, there are simply far too many factors in play to ever be 100% sure. All you can possibly do in this business is to tick all the boxes, what I like to think of as the big boxes and the little ones as well. Those little 1% ones that many overlook, they are add up and can often make the difference between a sale or not!
Your second question. You're bang on about the traffic issue and being switched on to that aspect of having your own site is great, because despite everything else you do, no traffic means no sales.
There are many things you can do to market a website, but it all comes down to how much you can afford to spend. This is where the rubber really hits the road, it's the most important part of all in my opinion. Marketing drives sales, there isn't any ifs, buts or maybes, marketing drives sales ... that's just a fact.
In today's market, Social Media is where most money gets spent. Now if you aren't switched on in that field, I would strongly suggest hiring a Social Media Manager to take care of that for you. They can be expensive, so my suggestion would be to have them take on one account only, my personal priority would be Facebook. If they are delivering you plenty of traffic from their efforts, then you can consider taking them on for more accounts, Pinterest, Instagram and so on, it really comes down to the type of products you are selling and the market you are targeting as to where you can get the most bang for your buck with social media marketing.
I wouldn't suggest just going to a social media management company straight off the bat, sites like peopleperhour are a great freelance resource where you can post your requirements for contractors to bid on. Having competitors bid for your business is a good way of getting the best possible price.
Never over look eBay as a strong marketing avenue as well. People think of eBay as a very expensive option, but that's because they look at the platform as a sales channel. With your own site, you can flip that thinking 180 degrees and think of eBay as a marketing channel. Use it to drive traffic, not even try to make money from it. If you think of eBay in those terms, then it's not expensive at all, in fact it can provide some of the best value for dollar marketing you'll ever get your hands on.
Anyway, Pete. I hope that's given you some ideas moving forward, but just give me a shout anytime if need anything, happy to help in any way I can :)