Everything to do with using your own website to advertise your rental property. Design, usability, hosting, getting listed on the search engines, optimising your site, pay-per-click, etc, etc.
I´ve noticed that sometimes when you click on a link to go to a website, you initially go to an "Enter Site" page where you have to click on that to go the site´s homepage. What is the point of that? Does it serve a purpose and does it not just give people an extra click to have to make to get into the website?
I don't know the answer to that one but I really don't like them and sometimes don't bother with the extra click, I just wander off somewhere else,hopefully to a "enter here" free zone
It's called a splash page, and it's a relic of the bygone days of web design. Although your reaction is (I think) the same as most people when they encounter one, there are still plenty of people who use them.
I think it's a nod to the days when people had slow modem connections, it let you load a page that confirmed this was your site and perhaps a few lines of info
rather than them not bothering to wait for your main home page