Depending on theme, the frequency of payout varies greatly. If you have one of those multplier type machines (like 3x, 4x, 10x, 12x, etc), you will have long droughts of no pays. As a rule of thumb, the smaller the multiplier, the more often you will get pays. 98.6% is about as high as you can go on slots. But you need to understand, the payback % is a statistical number based on millions of plays. Some of those pays will be HUGE, thus skewing the totals in the short run, but to "make up" for it, the machines pays little the other times. Over a short sample size, you will can get these long droughts of no pays. If you want more "action" get a multi-line game, it gives the impression of getting paid more, but you have a lot of losing spins, even when it pays (i.e. bet 45, get paid 5).