And they keep on coming. More airfare search sites and tools keep popping claiming to get customers the lowest fares.

They're all great, don't get me wrong, but they're all similar, and use the same airfare data: Hopper, Adioso, Hipmunk, Google Flights, and all the ones that came before.

What's ironic is that they're all piling on just when the game is sort of over. There are only four "major" U.S.-based airlines left standing. Gone are the days when airlines would knock each other over the head with crazy nationwide fare sales.

If you've been following Airfarewatchdog since our start, or before that when we did this for AOL, you'll remember the $88 round trip nationwide fare wars, back when there was an ATA (formerly known as American Trans Air),  a Northwest, a Continental, an Independence Air, America West, Skybus and all the rest. RIP, my friends.

So the new sites are fine, but none of them are true "disrupters" (I hate that word, but it will do for now) --or companies that will change the way business is done.

To truly change the game, an airfare search site would have to do all five of the following:

1. You tell it when and where you want to go, your specific dates, how many people, and so on, and if a fare goes way, way down for your dates and place, it automatically books you on a 24-hour hold. If they don't hear from you that you want to book the trip, it cancels. Fares plummet all the time, but you need to act fast to get the best deals. What if you don't open the alert email, or see the fare, before it's too late. This would solve that problem.

2. You tell it when you can travel, and you get alerts by email or tweet or SMS showing the 10, 20, or however many cheapest destinations. For example, I can only take vacation July 4-10. Where can I go cheap during those exact days? Show me a list.

3. Provide a truly flexible date search calendar over almost an entire year, like Travelocity (and Easy Sabre) used to do back in the infancy of online airfare search. But unlike those days, all dates showing a valid fare would truly be available. No hunting and pecking.

4. And to be truly revolutionary, when it emails airfare alerts, it should allow you to eliminate airlines you don't like, or only choose only the ones you do; specify a maximum price and nonstop flights only; and only send alerts on SkyTeam if that's your preferred alliance.

5. And how about a search engine that will tell me that although Houston to Honolulu is $800 RT, Dallas to Honolulu is $340 round trip and Houston-Dallas is $128 round trip? Now, that would be a game-changer.

True,Google.com/flights will let you choose a departure and return date and show you a map of some low fares, but it's not exactly "curated" --as in just show me the lowest fares. Or just to the cities I want to visit.

And Google.com/flights/explore is a cool tool, with its filters and ability to show you the top fares, month by month (it doesn't let you enter exact dates), from your city to, say, "Asia" or "New York" or "Mexico".

Adioso is pretty cool since you can ask it to send you alerts based on a query as plain-English as "New York to anywhere in June for a trip of about 2 weeks."

Hipmunk is, well, cute.

Hopper is inspirational. And also has a cute logo, although our Wheaten Terrier logo is the cutest of the cute. Actually, he's fierce.

But until something really different comes along in the airfare search sphere, I'm not going to get all excited.