I have to concur with most of the people here, when I purchased the Piriform Suite, even the website specifically said that I was purchasing the professional software, not a subscription. The website does in fact now specifically say they are selling subscriptions, but in the past it did not. The original sale of this product was for the product itself with automatic updates and tech support, lifetime.
It's extremely scummy when companies do this to their customers and it happens way too often in this industry. Your software is going the way of StarWars The Old Republic, into the trash can.
PS: The [censored] popup ad for the Pro Plus package (Which is what a lot of us bought) still does not say anything about a subscription. It's not until the next page that there's a mention of it, and it's not particularly noticeable