But if you are looking for maximum conversion within the shortest period and with the 20% offer I am gonna like to work with this and am going to suggest my best working sales strategy on the internet that has always yielded positive result.
I don't know what your site is all about,but if it's niche targeted or related then we are good. All we need is to run facebook adverts,which means you have to create a facebook page,though we don't need this but it will enable us get cheap clicks from facebook and we design a landing page that will automatically redirect to your own page
(off site ads cost much on facebook which makes facebook believe people will leave their site but on site ads cost less which means you are on facebook and facebook thinks you will still click on more ads)
Then this people comes to your site for as low as $0.01-$0.10 per click . And Some would buy immediately while 80% would not buy.
Here is where retargetter comes in place,you will add a little script to your website and hence it tracks the number of people coming to your website,and you can hence, offer them a 10%-20% discount on what they offer and this ad is really cheap which serve on cpm model.
instead of waisting ad money on google adwords,where you can't target probably age 25-35,interest related to your produc you can actually do that on facebook and get 100% ROI.
Am actually good at this so it's easy for me. You can feed me back on what you think