Well i think there are the things that are making no use of such coupons especially with new hosting.As you can see the thread by lemon where0.50$ per month hosting with coupon but later in just few days the hosting is gone.I am telling this because many times we buy hosting for 5 years due to some coupons or advantages of some code.Also many times the company makes the offer for 5 year hosting package like hostgator always announce rates for 5 year package so when we check the rates it is almost double for a one year hosting if considered monthly.
Sorry if i forget to mention it clearly in my post.I have edited it now.