Hi guys search engine have huge traffic if your keyword rank well on it. As far as i think if your keyword will on the top 5 on on search engine then it will give huge traffic for your website. So, i can say search engine is the best for traffic point of view.
Search engines are the best source of traffic. Traffic from search engines will be classified as they have not landed on your websites by following some attractive text or incidentally. However, they have found on your website what they were looking for. People coming from search engines are very specific about their needs and queries. If they land on your website, it means they have found your website most relevant out of billions of results.
Definitely search engine is the best source for getting real traffic. If you optimize of your site then you must do seo.
Really depends on what you're marketing. If it's a service (B2B), you won't get much direct traffic- ie returning visitors and social media isn't too good either. If it's a shopping portal, it'll be the other way around. If it's pure online information, then it'll be the mix you referred to. However, social media and even bookmarking sites will drive traffic for 24-48 hours after a post/ link has been placed! Edit: Based upon the posts above, i'd probably add a rather major revision. They're all great for a short term bump in traffic, but don't compare to fresh content, which, once you have a site with a decent volume of visitors, is great for keeping them coming back!
There is no real percentage amount to base traffic on. But you need to focus on generating traffic through search engines, search engine traffic is a long term method.