This is old news by now, but no, not everyone is contented with ad revenue. Since ad rev. relies on people reading/liking your comic, it varies a lot, and is subject to change depending on what else is popular that given day, whether or not you're ill and can't update regularly, whether a scheduled hiatus falls in one month or the next, etc., etc. It also depends on the individual circumstances of your readers - some months, they might have time to read your comic a whole bunch, and some months they might not have any time at all, which impacts the number of views.
Also, the number of views does not equal the number of ad-impressions, as not everyone who browses Tapastic comics have ad-block turned off.
Support pledges are a more reliable form of income, as the Supporter commits to pay a certain amount per month, and it also allows them to give money to their favourite artists without having to turn off ad-block, which most people want to keep turned on to avoid ads and possible malware.
But the Support Program is going away, so we'll have to make do without it, and hope our Supporters migrate over to Patreon.