1. Why Bitshares?
As you may know, Bitshares and Steemit are both created by 
After steemit shows the success to combine blockchain and blog, there will be more blockchain based services and their cryptocurrencies, plus those existing bitcoins, people need somewhere to trade them securely. There are some major reasons to use bitshares:
a. It’s decentralized and transparent, you have lower risk to be goxed. If you hold the bts token or bts pledged smartcoins such as:bitusd,bitgold, you are totally safe, just as the Steem Dollars.
b. The transaction and trade fees are much lower than in the traditional exchanges.
c. Extemly fast, the confirmation is less than 3 seconds, and scalable to 100,000 transactions per second.
d. Bitshares will grow gradually with Steem, now it’s the golden time to buy some bts in low price.(the market cap is 12 million now, when steem is 269 million)
2. How to trade at bitshares platform?
As you trade at the other exchanges, you deposit some money , and they credit some IOUs to let u trade. In Bitshares, there is also an iou called open.steem, which is created by ccedk.com. So let’s see how to trade at bitshares platform:
a. First, register an account freely at Bitshares.openledger.info
Remember to backup the wallet and your password!
b. Send your steem to openledger with your own memo. You can also send bitcoin to openledger too.
c. start to trade! Now there are two pairs: steem:bts or steem:btc
d. You can withdraw your steem when you want to power up.
See more informations:
Bitshares.org
Bisharestalk.org