Visitors are annoyed for couple of reasons. In their subconscious mind they decide whether they will stay or not in this site. If the visitors interest is not considered, then he may leave. There are six reasons that make visitors to leave,
Not being mobile friendly
As the bounce rate is increased through mobile, the rate of searching in increasing. If the site is not mobile friendly, then the user returns to google search after clicking search site. Therefore, bounce rate increases. Make your website mobile friendly to lower down the bounce rate. Also make front, hyperlink, page navigation mobile friendly.
Effect of unrelated headline
Attractive but unrelated (If the content does not match with the title) title may increase traffic but it also increases bounce rate. Traffic will lose faith on the site and visitors will decrease. Sharing to social media will also decrease.
If your homepage possesses a lot of popups, then that will annoy users. There may be e-mail signup popup but that must have a close button to its corner. Think yourself as a user, after entering into a website if you are attacked by many popups then it will annoy you.
Effect of less informative and messy article
To read web page fluently in a short time, well organized and informative article is necessary. Remember that well and informative article will hold up user for long time.
Effect of relatively slow site
If the site is low, then it will reduce conversion rate and many of the user will left the site before it is fully loaded. Page loading is very important. About 40% of the user leave website if loading time in more than 3 seconds. Besides, the site will lose its rank in google if the site is slow.
Effect of unattractive pictures
Think of books that reads well. It feels comfort to read a book with cool pictures. The same happens in case of website, Nice, clear and appropriate pictures attracts users. It helps users to return to that page again.
SEO or search engine marketing is directly related with above issues. The pages that do not attract users is not suitable for SEO. Therefore, pay attention in site designing.