The ad revenue on Tapastic remains in continued decline. Michael said once that its a "race to the bottom". Adblockers are experiencing double digit growth and over 30% of all US browsers now have adblock. On top of that Wall Street Journal reports 30% of all internet traffic is Russian/Eastern European bots that refresh ads tens of thousands of times driving up impressions and costing advertisers millions in lost advertising money. The bots are paid kickbacks by third parties. There was a time when some creators on Tapastic were using these third parties to send tons of bot traffic to Tapastic to run up ads but they've been since removed from the site.
What this all means is that display advertising is rapidly losing its value. 30% of US users don't see the ads, 30% of the ads are just bots, so only 40% of the ads are actually seen by a pair of human eyes. Click thru rates are now 1 in 1000 which means it takes 1,000 impressions for someone to click an ad. A lot of advertisers want $10 CPM, or $10 for 1,000 impressions, which means $10 a click. If you are selling cars, no problem, if you are selling things with a margin under $10, each click will be a net loss.
This is why you are seeing CPMs falling more and more. Before DeviantArt closed up their third party administered ads, they were going for as low as $.04 CPM. In other words, 2,500,000 impressions for $100. If you look at Project Wonderful, a lot of the bidding there is comparable to that.
In order words don't make Tapastic ads a part of your revenue plans.
Display ad revenue is on the way out. Which is why Tapastic decided to switch gears to tipping. Fortunately video ads have much higher engagement rate and advertisers are willing to pay well for it. Hopefully that lasts for the long term but nothing is for certain. Which is why Tapastic is also looking at offering other coin earning opportunities (no idea what they are). Perhaps they will go into the survey business which is crowded but appears strong and perhaps even micro tasks. As more coin opportunities open up tipping should become more and more vibrant and a possible alternative or supplement to Patreon revenue.