Bad KLM, bad KLM
When booking a ticket with KLM and you have just clicked on Submit, you get this weird warning of a certificate that has now be renewed (expired two days ago). Was my credit card number compromised? I used the proper www.klm.com website and www.klm2.com appears to be a lifestyle version. The domain record whois.domaintools.com/klm2.com for KLM2.com shows that it is an official KLM owned Website.
KLM, I believe you have missed several opportunities for flight sales this weekend.
Tip: It appears that when you book tickets online, you can save over 25 euros if you select your dates carefully when searching for availability. That is, when you do a search for a Friday to Friday trip, you get results for multiple days so eventually you can book a Wed to Wed trip. However, if you do an initial search for a Wed to Wed trip, the ticket price is much cheaper for the same dates. Try it out yourself!