I like the way your thinking in regards to putting in certain processes to build a complete strategy, the email newsletter, the blog and so on. I would start by saying that if you are in a position where you are making 10 dollars an item, then that's actually pretty good I would say. As you realize, you are dealing in a crazy competitive market and profits are usually very thin across the board.
I look at eBay like I do a shopping mall. Imagine being a business that is opening up a store in a massive shopping mall that already has 300 retailers selling the exact same thing as you will be all lined up door to door..... you would probably be crazy for even considering doing something like that lol. Well that's only 300 competitors you would be up against, you're probably taking in the thousands of competitors you are up against on a site like eBay with a lot of items. So that kind of puts what you are up against into some sort of perspective when it comes to eBay.
Having said that, my personal opinion is that you need to be where the traffic is. Having your own store e levels down from the other 300 up top is great if the traffic is coming down those 3 levels, but the trick is getting them down those 3 levels to start with. What I am talking about of course is having your own independent site. I think the best long term strategy is to have both, your own store 3 levels down on your own, but renting space on the top floor to promote where you are.
That's how I see eBay long term. You're focus should be on building and developing a quality site of your own, then you use eBay more as a marketing tool. More and more sellers are doing this now, which of course is driving eBay prices even lower. What you do is sell at cost, I mean your total cost, so you cover the item, the shipping and the fees and you get ZERO from the deal
OK, so ZERO cash, but valuable marketing exposure. Because now you have the contact details of the customer and you can market to them directly. 10% off your next order over 50 as a thank you for your purchase, join the VIP club and get great monthly discounts and so on. The key is getting that open marketing exposure outside of the eBay walls. Now that all takes time to build on, but it's the end game strategy that I would employ personally if I were still involved in e-tail
Regarding writing good copy for a blog, you know I think there is a definite mathamatic equation to doing that. That exact formula probably depends on your products really, but key points that I think make good copy are a level of humor, information and the ability to create a desire for the product. Not everyone knows what they want, and the mistake a lot of sellers make is that they think they do, so they don't try hard enough to create a sale.
I started selling Amway door to door when I was 15 years old lol, so I learnt that it hurt to get your nose slammed in a door very early, but I also learnt that people could be talked into buying a product that they didn't even want when they first opened the door. A good salesperson can sell, they sell, I mean they don't just show people things that someone is eager to buy, we call those presenters, they aren't salespeople. The art of selling is to create a desire, give the customer the reason they need to buy the product, that's what a good salesperson does.
So when writing copy for anything, blog, item description, whatever it is, you should always be thinking about creating that desire, looking for triggers that your product presents that you can pull. They're all there, most are hidden, but the true art to online marketing in that form is finding them all and exploiting them to create that buying response from your customer.
You're on the right track Juan, you're thinking, you're not just plonking a product there and wondering why it isn't selling. That thinking is 90% of the game right there!