|Stop Trying To Hide Your Ads And Make Sure The Are Seen!|
While most people will enjoy putting their ads in places they get seen there are some people out there that get confused with Adsense's own terms and agreements. When Adsense tells you not to blend your ads into your site it is not telling you to make sure they are invisible. It is telling you to make sure they are not obstructing the theme or the layout. Anything that might seem annoying rather than helpful.
So what would I consider to be a hidden ad? Any ad that is lost in a sea of content or at the bottom of the page is basically a lost ad and bad for your website. If you want to place ads in the middle of your content use in-article ads or mixed content ads to really make the most of that in-between space. But at the bottom of a page, I would stick to Matched content ads as they can help people find more related content on your own site or hopefully go to a different site via the advert.
If your site hs a coloured background make sure the colours of your text ads are a stark contrast to your own site theme. So if the site background is white, go for red or green ads. If it is black go for white or maybe red. Do check out my post "Which Is The Best Ad Style To Choose For My Website?" for better options relating to this.
While I will not go into details of ad placements in this post I do suggest you don't try and "blend" your ads into the website, but rather make sure they are in those visible and eye-catching places. When Adsense tells you to "Blend" the ads into your site it means to make sure they are not the focus of it. That the ads are helpful rather than a hindrance. I have come across several sites that have ads below the fold and nothing above it which is no good at all. Having ads is not something to hide and be ashamed of, you should see them as extra content that will help people get to the services and products they want.