I've been subscribing to Boingo the wifi service that connects you to hotspots which would otherwise want to charge you. I don't seem to need it that often, but £3.95 a month is OK as insurance. But I just noticed on my bank statement that £3.95 is now £5.95, a 50% hike.
So I've searched my emails for their notification, and found it in trash. It is headed 'Boingo Mobile: More Hotspots, More Secure, More Value' and I trashed it because it appeared to be a marketing newsletter.
It does tell me about the price hike... near the end of the email which I stopped reading after the title. Loss of trust --> do I really need it? --> cancelled.
I'm also wary of products I can't pronounce.