Dozens of companies in US vacation rentals, including many airlines in US vacation rentals, sell tickets online to US vacation rentals, so it pays to shop around. Most sellers take credit cards by e-mail or over the phone and send out tickets by overnight mail at no extra charge. If You're entitled to a price break in US vacation rentals, actually you are taking on work that would otherwise be done by a travel or an airline-reservations agent in US vacation rentals. In practice, there are glitches. The responses we got were incomplete and very inconsistent.
Much smaller sites can be more user-friendly.
In the near future, though, on-line agents may gain some more control. Streaming videos of beach resorts you're thinking about US Vacation Rentals for a vacation and getting a look at the home or resort you want to book. Also receiving a weekly bulletin alerting you to last-minute bargains at airlines and hotels that are trying to shed unsold inventory. This is one advantage, in theory, and is the beauty of the Web. With travel services that's already been happening, except on a smaller scale.