I started off with a $100 bing ads coupons spent $80 with no conversions, oh well learn from testing right? I found another coupon code for bing ads in my hosting for $100 and applied it. did some optimizing and tweaking went to bed, Woke up to conversions! You're ROI may not always be up so tweak, optimize, make your ads relevant and use good keywords. Also I finally have access to $500 bingads coupons so ill be advertising for free for a while and scaling like mad! Point of this post is that no matter what you spend you need to keep trying and changing things. I can't give away my winning campaign here of course, you wouldn't either. Spend some and make some! but be frugal about it and find those coupons and use them!