If you would like to add certain fields in to the system to allow you to gather the relevant and important information about your customers, you are able to customise and add those options to the system. So not only do you have the default ones but you can add your own.
These will enable you to start segmenting and personalising your marketing to gain the trust from your customers and get those sales rolling in. If you are interested in this, they are called "Custom Fields".
You may also want to add your own options to select for "Lead Source" so you are able to analyse the best marketing strategies and this you can, so along with the default ones why now add ones relevant to your business.