Beermoney question

Since the first of the month using 3 apps religiously I've cashed out almost $45 is there a way to increase that using only the 3? I've tried refferals but everyone has the apps allready pretty much.. had some refferal credit twice only have two refferals so one each outside of that nothing. Is there an easy way to get more refferals and to keep them interested so I keep profiting?