Making money from your blog: Change your ads

This is a point to be made several times but it’s so relevant and so often ignored or even unknown, that it deserves its own part in this world-famous-any-day-now series.
Most ad clicks come from first-time visitors, as your regular readers tend to become “blind” to your ads - they filter them, unconsciously. That is mostly unavoidable - though it’s still desirable to convert newcomers into regulars, as there’s still a chance they’ll click on an ad, but, mostly important, they may link to your blog, make it more interesting with their comments, and tell other people about it.
But there’s still something you can do to reduce the “ad blindness”, and that is to change ads from time to time.
Without wanting to go into psychobabble, it’s a bit like this: it’s as if people have a mental “ad filter”, which works for ads in a position they expect, or of a type they expect. So they don’t even look at those.
The idea, then, is to go around that “filter”, and surprise people, so that they see ads where they don’t expect, or in a different format.
So, my suggestion is this: from time to time (I’d say at least monthly), change your ads. You can do one of the following, or a combination of several:

change an ad’s size or format
move an ad to a different position
completely remove an ad for a while
add a new ad somewhere (assuming you don’t already have too many, of course - you don’t want more ads than content)
change an ad’s provider: for instance, replace an adsense ad with an affiliate ad, or a blogads one.
change an ad’s colors - if it used the colors of your site, try using different, more visible colors for a while. Conversely, try changing a “blended in” ad to colors that stand out more.
if using non-contextual ads (such as the default Chitika mode), try changing the keywords - possibly even replacing them completely with a bunch of new ones (but save the old ones somewhere, so you can compare results).

This may sound like a lot of work, but can help a lot in terms of click-through rate (CTR).
One other reason (and a very important one, too) to do this is that you’ll be able to learn a lot about which ad formats, positions, colors, ad providers, keywords, etc. work better or worse. Remember to configure channels, if available, for each type of ad, so you can track which ones give you a better CTR, and more money.