On a per product basis it's relatively easy, but the question is what the average is.
My philosophy is that if you know you're making money, it's not so important to track exactly how much. I'll probably need to adjust that when I file my first tax return next year, though (so not looking forward to it.)
A lot of the people I follow in the industry have blogs and alternate income streams outside Amazon/eBay. (Paid lists, software, coaching, paid groups, etc.) Definitely something I want to do but I need to get my business onto maintenance mode first and definitely not happening anytime soon.
My short term goal is consistently 100k/sales a month, and my long term (6-12 months) goal is 250-500k/month.
Feel free to ask me anything here, though.
Many different products, really whatever sells fast enough with a large enough margin. I've sold things for less than $5 and things for over $1000: generally the cheaper the more it sells.
What margin I want depends on how fast it sells, competition, and some other things, don't have hard and fast rules as of now.
Many categories, from toys to electronics to tools to grocery to beauty. Amazon requires approval for grocery, health, and beauty, so there's typically less competition.
2. how do you write product descriptions and copy that will attract buyers especially on amazon?
Finding items: I look for items that are already selling well, ideally multiple times a day (you can determine this from sales rank and keepa charts, easy to find out how to read them, use google and you'll find many blog posts). Sometimes I'll look at a store and see which items are good for amazon (enough margin, fast selling, etc) and sometimes I'll look at amazon and then try to find items at a store (when I have an item that does well, I'll often look for other items from the same brand or category.)
I use oaxray, a paid tool, costs $100/month to find products. It searches through a webpage and tells you which products are profitable for amazon, then I filter through those. Recently I've begun training employees to use it and make me lists of finds which I then go through.
2. Some stuff is bought on sale, which may be over by the time the item sells
3. Yes, people absolutely pay a premium for not having to go in store. Even stuff I can buy online people often pay more on Amazon. I do a lot of drop shipping from retailers directly to customers.
What I've learned:
1. Not all rules matter. A large part of my business is stretching certain rules, either from the marketplace, or from the source (e.g. a store that doesn't allow resale). That said, you can't get away with breaking rules unless you have a very good understanding of why the rule exists, who's motivated to uphold it, and generally what the risks are. Don't screw over customers.
2. There's a lot more to be made by taking risks than there is to be lost. I've easily lost over $1k multiple times in various ways, but when I "win" it's to the tune of 10 or 30 times that. Take smart risks, only where the realistic upside justifies it.
3. Be willing to pay for information. There are courses out there in almost any topic. Personally I've largely carved my own path and paid very little , but I'd still recommend courses for others. Also read a lot of whatever free information is out there, and network with people who have more experience.
4. Don't do too many things at once. It will kill you. I've been full time in college and it's extremely tough to balance everything. Delegate as soon as you can afford to, anything others can do that doesn't take a lot of brains pay people to do.
5. Don't be afraid to scale, but do it slowly. My first purchase of over 10k was 6 months after I started, iirc.
(Several of these are probably specific to this kind of business, may not be generally applicable. Startups have a much different road where profitability isn't the most important at first.)