Endless Vacations is just one of RCI's names - they use it on their member's magazine. Extra Vacations is what RCI calls the last minute inventory, "excess" inventory (commonly offered for cheap rentals) and developer rental inventory - all offered for cash rental and much of it for last minute exchanging as well.
It looks like anyone can buy a certificate for $500, and keep it or give it as a gift, and that person can look through whatever inventory is assigned there to select a trip.
Would not surprise me. Developers (like DVC) may get a certain number of these for pennies on the dollar to encourage use of RCI and as part of the incentive for the developers to sign on with RCI. They give something to the developers to offer potential purchasers in their sales pitch.
I am also wondering whether this updates the first of each month, as there seemed to be more choices today.
Updating of RCI inventory is a live process for some things. As people deposit their weeks, they may show up within a day or a week. As people cancel previous trades, they show up almost instantly. RCI used to do nightly uploads of bulk deposits from developers however, recently, bulk deposits have been spotted and reported right in the middle of the day on TUG and TS4Ms so it seems that they're now doing these updates "live" as the developers send the bulk spacebanking data. Weekly computer "maintenance" shutdowns may occur on most Saturday nights after 8pm eastern time, after which the inventory is often noticeably different on Sundays. Have never heard of anything on the first of the month nor any kind of monthly basis.
...there were lots in the Canary Islands, in some parts of Mexico, Branson, Venezuela and some even in NH or VT. No California or Las Vegas or Hawaii, and more limited in the rest of the US.
Right, mud season in the mountains, all-inclusives that charge hefty fees and overbuilt areas. My preference with these kinds of things is to hunt for a great Sighting within 60 days or just plan in advance for a beautiful resort vacation in an area that happens to be overbuilt (Williamsburg, Orlando, Branson, inland golf retreats), a remote getaway or I choose a shoulder season, like October at the SC beaches.
Since the greatest amount of inventory available for Extra Vacations is going to have a check-in date within the next 60 days, you'll see more inventory when you are looking 60 days before a slower travel season (like early autumn or in the offseason, like non-skiing winter locales) than you will, right before a popular travel season, like the coming summer. If you're hunting for that great, unusual, in-season find, then checking frequently and using the Sightings boards will help year round. Hope that makes sense.