Making money by selling things online is something that a lot of people do. It can be a great way to make an income or supplement your current income and that is why so many people are involved in it. However, it is important to think hard about what specific items you are selling as what you choose could have a big impact on your success.
It is worth starting by doing research on various sites where people sell things. Sites like ebay, Amazon, Etsy and other marketplaces can be a great resource. See what is being sold on there and how many people are selling those things. It can be possible to see what has sold and for how much as well, which is a great way to see not only what people are selling but actually what people are buying. It is easy to put something up for sale, but not so easy to actually find a customer, so it is really important to make sure that there are some people available that really want to buy the items.
It is also worth finding items to sell that you know something about. You will need to be able to source items that offer good value for money and answer questions about them and so finding something that you know about it good. You will also need to think about where you will store the items as you will need to keep a supply of stock and either store it in your home or pay to store it elsewhere. If you are selling large items you will obviously need more space to store them and therefore if you do not want to pay for storage and do not have a lot of space then you may have to go for smaller items. Postage is also worth considering as if you are sending items out to people then you will need to consider how tricky it will be to pack them up and to either carry them to the post office or have them collected by a courier as well as the costs of this.
It is worth being aware that the market will change from time to time. You may be able to make a lot of money selling certain items, but find that after a while people are no longer interested in buying. There could be lots of reasons for this such as a change in trend, people spending their money in a different way, change in the competition that you have or many other things. Identifying why demand changes is difficult and probably not worth the time and effort but being aware that it can change and that you should make efforts to check for it and make sure that you adapt to the change in demand so that you can continue to be profitable.
So it is not possible to say that one specific product will be profitable for you because the demand will not always be the same. However, if you do research and consider what space you have for stock etc, then you should be able to find something that will suit you and the space that you need.