Beneficial feature of Linux:

• Security
• Open source (open on net)
• Free distributions
• More features
• Virus protected (3/4 counted in last 10 years and removed)
• With the help of wine software, we can run .exe files
• Easy to resolve the problem (easy account database)

COST:
As you might know that windows based software and server services are very costly, on the other hand Linux based software and services are absolutely free. Most of the company who can even afford windows and windows based software are now using Linux and open source software. 
Little example just see the cost of Microsoft office below:

Microsoft Office 2007 Price:

• Microsoft Office Home and Student 2007 Price: Rs 3,025/-
• Microsoft Office 2007 Standard Edition Price: Rs 14,500/-
• Microsoft Office 2007 Professional Edition Price: Rs 16,500/-
• Microsoft Office 2007 Small Business Edition Price: Rs 15,700/-
• Microsoft Office Ultimate 2007 Price: Rs 26,800/-

While OpenOffice 3.x with almost all features and more comes Free of cost.
Now it is very clear why so many people are using Linux and Linux based software.

How Fast and Secure it is:
Recently Microsoft introduced Windows 2008 Server Core, that has no graphical interface to make it secure and to reduces the requirement of regular HotFix, and graphical interface require more HotFix an updates. But still you need to have atleast one Windows 2008 Domain Controller with graphical interface in the network. That is the requirement of Windows Server Core.

While in Linux, Most of the server engineers prefer using Command Line Interface, most of the servers in Linux can be configured using command line without ever requiring graphical interface. You can disable / enable, install / uninstall graphical interface any time in Linux.
Linux has inbuilt feature of Iptables and Selinux to improve security. Iptables allow and prohibit IP traffic based on Port No, IP address, Domain Name etc. On the other hand Selinux provide file level security.
Most of the virus is made to infect or corrupt MBR, NTFS, FAT FileSystem, file located in c:/windows, c:/windows/system32, exe, dll, inf files etc. Having different file type (*.rpm, *.conf, *.tar etc) and file system (ext2, ext3, ext4 etc.) Linux has really saved us from the infection of virus.

Compatibility with Windows:
I personally believe, if an Operating System does not provide compatibility and connectivity with Windows or Linux, there is a very less chance for that operating system to remain in the market.
In IT industry, Windows and Linux operating System goes hand to hand. Linux has many features that provide connectivity and compatibility with Windows Operating System. Like file created in MS Office can be easily open in OpenOffice, which is Linux stuff. Samba service in Linux provides data and printer sharing not only with Linux but also with Windows.
DHCP Server (in Linux or Windows) not only distributes IP address to their own Operating System but to all TCP / IP based Network Operating System. The same compatibility is provided by DNS, Apache, NFS, FTP, Telnet, Proxy and all that.