To solve the task, I'll go through each gap and provide a suitable word, ensuring the sentences make sense in the context of eBay:
design - One of the design features of the websites that have been very successful in recent years is eBay.
other - On eBay, people take things that belong to them and offer them for sale. Other people offer money for the items.
bid - The person who offers the most money wins the item.
credit - They then pay directly and receive the item by cheque or credit card.
simple - eBay has become a very popular way of buying and selling.
times - Even if you don’t have the time to go to the shops, you can often find something that you want on eBay.
buying - Most of the items are people buying secondhand.
sell - Most of the items are people buying secondhand and even selling.
internet - However, you do need a computer and an Internet connection.
million - eBay has a million of happy users.
These words fill in the gaps in a way that makes the passage understandable and logical.