High Quality Backlinks are the secrets of profitable website flipping. Backlinks means inbound links indicating towards your website. They are very important for better search engine rankings. Search engines consider backlinks as votes. So if your website has one backlink than it means that it has one vote.
If you want to flip your website for a huge profit than you should start building the all rounded quality backlinks portfolio from the first day you buy a website. Basically quality and quantity of the links both counts. The relevancy of inbound links also taken into consideration by the search engines.