This is the first time I've looked at this plug-in... But, I have to say, the gigantic blue button square in the middle of the index page of the plug-in site that says "See Plans & Pricing" seems like kind of an obvious clue, to me...
But yes, the short version is, in order for this to be a useful tool for any except the most basic and untraveled sites, it's gonna cost you almost $80 per month.
For most WordPress users, I'm guessing that's more than you spend on hosting and internet access, combined.
Here's the thing: From my understanding, it's not a hundred polls you get at the free level, but 100 survey responses per month. After a hundred people answer, you can't see the further answers, until you pay.
So... Basically, I guess, the free version is fine if nobody ever visits your site except your immediate family and your cat...
Even the "Pro" version - $16.66/mo - only allows you to see the first 1000 responses per month. That's over a penny and a half per response for, basically, one ping to their servers, and a database report when it's over.
If you only do one survey per week, and only get 250 visitors who want to participate in these surveys, you'll get your data. Any more than 1000 answers in a month and, again, they hold the additional data hostage until you upgrade "Corporate".
$74.92 per month for "Corporate" and unlimited answers. Four and a half times the "Pro" rate. So, if you're getting 2000 responses, on average, you're going to pay almost four cents per for less server traffic than one tweet, and a database report at the end.
After five minutes research, the only thing that remains interesting to me about this plug-in is that -anyone- would be gullible enough to pay that much. I mean... For $899, someone with the intelligence dog gave a soda cracker should be able to learn enough PHP/MySQL, CSS, etc., to code their own survey plug-in and pay their web hosting for the year.
I'd be happy to pay for the not inconsiderable power and flexibility of a service like this, but the pricing plans would have to at least pass the laugh test.