Last Minute Travel Club is a travel membership site associated with Last Minute Travel (lastminutetravel.com) They typically charge $9.99-$49 for membership. Right now you can get a free 1 year membership just for signing up. No personal info or CC required. You will also receive a $25 off booking coupon after sign-up.
This is worth doing. The free offers only come out 1-2 a year and LmtClub sometimes has the best ota rates, especially for Las Vegas. They appear to have access to the same opaque rates as priceline, hotwire, etc. Note that because they are not available to the general public you cannot use them for best price claims. As always comparison pricing is necessary when booking. LmtClub is just one of many options. In our experience there are often better values available if you account for direct booking promotions/points/credit, when booking outside North America, or when good discount codes of 20-30% are available elsewhere.