[wtvanhest]

CTR ≠ Sales

Even more importantly, a high CTR with lower conversion rate would drive up your costs while lowering your sales.

In this case the first ad is very clearly for a game with a very clear target market. If I am in to racing games, I may click it and I may buy it.

The second ad could appeal to people strickly on novelty which means you may get a lot of customers who do not care about the product.

While the results of this post are very interesting and the conclusion to test everything is still good, we should look at the conversion rate to see which ad is actually more effective.

[jakejake]

Interesting point. Obviously makes a big difference depending on whether you're the advertiser (selling products) or the publisher (getting paid for clicks)

[goodside]

CTRs aren't irrelevant, since they're a concrete proxy for conversions that ad networks can relay back to publishers quickly, but nobody actually pays by clicks anymore. That was common fifteen years ago, but CTRs plummeted circa 2002 and never recovered. Display ad revenue is now invariably calculated from impressions.

[idoh]

I work in Facebook app monetization and mobile ads, it is almost all CPC and CPI. The ad ecosystem is diverse enough that different pricing models apply in different situations.