The answer is in three categories; Page Load Time, Keyword Selection, & Content Creation.
Page Load Time is the key to maintain your audience on-site, if your page load time is low your audience won't wait for it and would eventually bounce out.
Keyword Selection is way important if you want to rank higher in the right search result, use relevant keywords so that you get a more typical interested audience.
Content Creation is the land of all, because if everything goes well but the content is not up to the point and well maintained then you might have a problem in maintaining your audience.