Learn a Language in 10 Days ... Not Really
"Learn a language in 10 days" is an ad from a merchant that sells Pimsleur products. You can see this ad all over the place. It seems like they have taken a page out of Rosetta Stone's marketing playbook. Don't be sucked in by it.
I love Pimsleur, but there is a big difference between the way Simon and Schuster (the publisher of Pimsleur products and owner of the copyright) and the numerous salesmen around the internet market Pimsleur products. Simon and Schuster, although they are certainly proud of their flagship language learning product, don't make crazy claims like that, they market it a little more responsibly.
Pimsleur products are excellent and I recommend them for the right language learner, but only after you have researched the product, compared it with other products and tried it out (you can listen to the first half-hour lesson for free). You can't learn a language in 10 days with any language learning product - it's just a scammy ad.
I have tried to work with a half-dozen different independent Pimsleur merchants over the years and gave up on all of them for a variety of reasons. If you are interested in buying a Pimsleur product I recommend you buy it from Amazon. They are price competitive and offer better customer service than you will get from scammy ad-slingers.