week 8 online auctions

From this topic, it shows that how powerful online auction is. However, online business must provide easy and free way for both sellers and buyers to do their business, for example, free from the annoyance of complicated buying and selling process, virus. It also needs to provide services to protect customers from fraud  and establish an trustworthy platform for trading.

Q1: eBay is one of the only major Internet "pure plays" to consistently make a profit from its inception. What is eBay's business model? Why has it been so successful?

ebay's business model is brokerage model. As the picture above shows, the broker brings buyers and sellers together and facilitate their transactions. The broker (eBay) charges a commission or fees from the completed transaction according to the value of the transaction.
why eBay is so successful:
1: it brings buyers and sellers all over the world together which benefits every party. sellers can reach more customers from all over the world. it also makes buyers easier to make purchase decision because they can compare and choose who they want to deal with.
2: it brings sellers together, which can increase the competition. through competition, buyers can get better quality products with better price.

Q2: Other major web sites, like Amazon.com and Yahoo!, have entered the auction marketplace with far less success than eBay. How has eBay been able to maintain its dominant position?

Those can be understood by their difference. 

eBay and Amazon:

1:eBay can sell almost everything, Amazon limits the sellers for certain categories and items. 

2:eBay is a site for both company and individual sell for auction. while Amazon is retail companies that sales items online. people can sell anything on eBay, but on Amazon, they can sell only whatever is available on the website. if it is not available on their website, you need to recommend it to them, and after their approval, you can get the chance to list your items on Amazon. 
3:Amazon has lesser visitors. if you sell things on Amazon, you need to be patient.
4:In Amazon, you name your price. however, In eBay, you may sell things in a much higher price than you originally purchase price.
eBay and Yahoo:
The problem yahoo auction has is that sellers need to register before they list items on yahoo. sometimes the system cause problem, for example, Yahoo Auction keep signing people out when they want to list some items there.  some people says there is a problem on Yahoo auction search engine. when they put some key words into the search engine. the item does not match the words at all. in addition, Yahoo does not resolve the problem it has unless the matter brought into their attention.
see serious problem of Yahoo Auction http://answers.yahoo.com/question/index?qid=20080526051521AANpt9a

Q3: What method does eBay use to reduce the potential for fraud among traders on its site? What kinds of fraud, if any, are eBay users most susceptible?

ebay has ebay buyer protection to protect which is fast, easy and free of charge which illustrated in the video. eBay Buyer Protection covers items purchased on eBay with eligible payment methods that are not received or not as described in the listing. But there are also some situations that ebay buyer protection will not cover.
 see http://pages.ebay.com/coverage/index.html

ebay also has "fraud alert system" to provide customer the opportunity to make complain and solve the issue with seller.
common fraud on ebay are:
1:items are not as good as it described
2:seller did not sent the goods to customer after they pay the money
3:fake products 

Q4: eBay makes every effort to conceptualize its users as a community (as opposed to, say "customers" or "clients"). What is the purpose of this conceptual twist and does eBay gain something by doing it?

Because of the value they set as a community, it can helps ebay to increase their customers'(both seller and buyer) loyalty by provide a way to encourage buyers and sellers to communicate with, respect and trust each other. It promotes a safer, fair and trustworthy place for trading. This concept increased ebay's profit by 5% in 2010 according to its financial report.

Q5: eBay has long been a marketplace for used goods and collectibles. Today, it is increasingly a place where major businesses come to auction their wares. Why would a brand name vendor set-up shop on eBay?

eBay has nearly 94 million active users. It plays a  dominant role in online business. Users generally think they can get a more cheaper price on eBay because they can compare the product and price.

Q6. I have a few businesses, and I have used eBay for about 12 years on and off. Currently I have about 600 books listed on eBay (seller name ozrural). I stopped selling on eBay for a few years but they changed the rules this July and it is viable again (for me). What do you think changed?
According to http://pages.ebay.com/sellerinformation/news/feeupdate2011.html. Fix Price Final Value Fee has been reduced.