Question about Spread and comissions. And alsoe charting software.

Hello everyone,


so why some some brokers take commissions when you buy stocks while others takes their share from spread? Is there any big difference between theese brokers? Or the way they profit from customers and other small features are all their differences?

And I want t2w members opinion about FreeStockCharts.com - Web's Best Streaming Realtime Stock Charts - Free. For me it seems pretty cool. It shows real time prices, has a lot of indicators and dozens of fundamental data. But some people buy charting softwares which costs few hundrend or thousand dollars. Why? Does freestockcharts charting software is weak ( amateur level) compared to let's say market analyst 7?

Sorry for bad english. And have a nice day ^^