When approaching SEO it’s always a good idea to keep in mind what Google’s ultimate goal is, in regards to their organic search results. Since this is their bread and butter, they take the results, very, very serious.

In my opinion Google’s ultimate goal is to provide high quality, relevant websites that best match the search query AND intent of the user.

Based off of this assumption, my approach is to target and optimize my clients websites for only those search terms that are relevant to their industry/niche, and that match the query and intent of a potential customer. (see more here: http://www.lamontagnemarketing.com/2014/10/08/5-important-seo-elements-to-optimize-on-your-website/).

Additionally the level of content needs to be very high, as low-quality and thin content has pretty much been eradicated by Google (as it should be).

When you step back and put yourself in Google’s shoes, it becomes much easier to understand what’s going to work in the long run and what’s not. If you do this, you won’t need to chase the latest algorithm update ever again.

If you'd like to discuss in a bit more detail, I'd be happy to schedule a time to chat.

Hi! So there could be a few reasons why, however I would venture to say that Ad #2 more than likely has a higher relevance score than Ad #1. This would account for the difference that you saw in regards to the cost-per-click of each Ad.

If you'd like more info, Facebook explains Relevance Score and how it works in detail here: https://www.facebook.com/business/a/ads-relevance-score.