It's not a perfect science, so there's no way you could give a fixed number of pageviews for hitting the $25 threshold. The ad payouts fluctuate - unless tapastic has deals with people who are placing ads on the site with fixed prices, the number of pageviews needed to generate $25 will vary.
If you need something to aspire to, assume the average payout is about $2.50 per 1,000 ad views. You'd need 10k of views in a month to reach the minimum threshold. And that is if every single ad was paying out $2.50. Some pay more, some pay that amount, some pay less.
Either way, you're looking at 10k or more per month. So start cranking out updates and getting more eyeballs on your pages. LOL