Facebook advertising is not only for innovators and early adopters anymore. Thus, the competition and bid prices on the ad auction are getting higher as the market share grows - especially for mobile. In addition, Facebook is raising the level of competition: they served fewer ads in 2014 than a year earlier. Facebook wants to provide the most enjoyable user experience possible and cutting the number of ads is one way to do that.
Diffusion of innovations 
The growing number of advertisers is only one reason for the tougher competition. The quality of ads, more automated ad creation, Facebook’s algorithm changes and the increasing knowledge level of advertisers make it more difficult to win the auctions on Facebook. In effect, you are more likely to have issues with getting your ads shown on Facebook.
If you can’t spend your whole daily budget, the easiest fix is to increase your bid. However, there are also other ways to improve the ad delivery such as avoiding deduping, updating your ad creatives periodically, refining your target audience and changing the bid type.
The Fix #1: Be Bold and Bid Higher
We have noticed that some people are too careful with the bidding. Keep in mind that the Facebook ad auction uses maximum bids. This means that if you bid $10 cost per click (CPC), for example, you'll be charged no more than $10. And, in most cases, you'll be charged less. Even though it could sound a bit irrational, higher maximum bid generally improves both delivery and return on investment (ROI). With a low bid you can reach people that are easier reached, but don’t necessarily provide the ROI you expect.
The Fix #2: Use Larger Audiences With oCPM
oCPM identifies the people from your audience who are most likely to take a specified action – e.g. purchase a product at your web store – on your ad. However, the algorithm needs huge amount of impressions, clicks and conversions to work properly. Use larger audiences and higher bids to fix the issue.
oCPM for actions requires the conversion rate (CVR) of 0,5 % or more with a 1 day click-through window in order to work effectively. If you have trouble getting the minimum required conversion rate, you can try to change the action from eg. a web store purchase to a landing page or upper at the conversion funnel.
The Fix #3: Dedupe
Your own campaigns can compete against each other. This is due to duplicate targeting and causes delivery issues. You can prevent the problem by designing your campaigns carefully with the instructions explained in another article.
The Fix #4: Understand the Core Metrics
The ad frequency metrics give you an idea about the ad fatigue. If the same ad is shown too many times to the same users, it loses its power. Change your ad creatives periodically to prevent fatigue. In addition, having larger audiences for the ads help you to prevent the fatigue.
The most recent metric Relevance Score helps you to understand the quality of your ads. CVR is more important metric than click-through rate (CTR) since clicks don’t tell the whole truth.
Lastly, is your delivery problem the overuse of a small target audience, too low CTRs or something else? Before starting to fix the root cause, know how to define it.