If people leave too quickly they aren't seeing all that you have to offer.
Work on keeping people on your site longer and you will definitely notice an increase in opt-ins and sales.
Some tactics to try:
Link from one page on your site to other relevant pages on your site. If your site is about a particular theme, it should be easy to interlink pages that are related to each other. The more your visitors navigate through your site, the more engaged they become with your content. Therefore, your conversion rates should improve.
Write concisely and use formatting to break up your text. Imagine you are the visitor that just landed on your site. If the text is long, with no formatting to break it up, it's too hard to read. Your visitors are likely to leave your site in search of a site that is easier to read. Remember that on the web all other sites (your competitors) are just a click away. Try using formatting to break up your text, such as bolding key words, using frequent sub-titles, bullet points and white space between blocks of text.
Make it easy for people to order or opt-in to your list. Use calls to action to guide your visitors to take the action you desire. If they have to hunt for the order button or the opt-in list, you've lost them. Depending on the length of the page and the layout you could ask for the order (with text and order links/buttons) 2 or 3 times (or more for long pages).
Don't clutter your pages with useless information. Before you put any content, links, images or videos on your page ask yourself: 1. Does this enhance the visitors experience on your site? 2. Does it help you with your objective for that page (get the sale, get the opt-in etc)?
Determine the objective for the page. You should have a clear objective for every page - it may be getting the prospect to call, getting them to opt-in or getting them to buy. Your most prominent calls to action should guide people to take this action. You can have a secondary objective as well, just make sure your primary objective is what you deal with first.
Whether you are building a new site, or already have one, keep these items in mind and tweak your site to increase conversion.
