Advice on doing successful business

Doing business online is a new tend. But somebody has been somebody, somebody has been nobody. Why? I am a businessman.From the past
failure to the present success, i want to share my troublesome experience here.
1.When I start my business, i did not know how to make a plan, how to analysis the market trendency.
2.Pay more attention to sell while show little care to after-sale
3.Do not how to save money and time.Cost too much money in training.
4.Buy software with out considerate analysis.
5.Send messages to customers one by one. Advertising cost me too much money.
6.Never make a conclude about the maketing method.
...
Until oneday, my enterprise had to claim to go bankrupt. I had to think more and more. With more than 1 years preparment, i start my business again.
1.Be accuqiantance with the lated market tendency via multi-method.
2.Make profound analysis about my competitors, involving the operation concept, management method, product codnition..
3.Be consitant with the regular customers and find more potential customers(Thanks to iKode newsletter software-http://www.phpnewsletter.org)
4.Do the best after-sale service to win customers' satisfaction(Thanks to iKode helpdesk x-http://www.phphelpdesk.org)
5.Make a comtrast with different marketing solutions
6.Analysis the marketing, learn from each other and achieve the greatest progress.