The network never gave your show a chance. It was scheduled on a night no one watches TV, or put against a ratings powerhouse. The episodes aired out of order, and the time slot got moved. It wasn't marketed properly...you never saw an ad for it, and no one you know saw an ad for it. Plus, the show didn't have enough time to catch on, the network never understood it and wanted it to fail, the DVR numbers were great and the Nielsens are useless anyway.
Why do networks spend tens of millions of dollars on shows then treat them this way? I'll do my best to give you insight into why these things happen, or at least seem to happen. Be warned, you'll disagree with some and quite possibly all of it.
Okay, so here's why networks...
Schedule episodes of a show out of order
There are two main reasons this happens:
1) More people sample a show when it's new, so networks try to run the best episodes first. Sometimes this happens and viewers never know it, and sometimes it's pretty obvious and might do more harm than good.
2) Some episodes originally slated to air earlier in a season might have a problem and need to go back to the shop for more work, so they get pulled, fixed and slotted later.
Move a show to different timeslots
There are a few different reasons this might happen:
1) If it's a new show and it's clearly not working in its timeslot, it gets moved somewhere where it might work better
2) If the show is doing badly but the network doesn't want to just take it off the air, it gets put somewhere out of the way so it doesn't hurt the shows around it. For instance, a low-rated show won't funnel many viewers to the show that immediately follows, thus hurting that show's ratings too.
3) If it's the start of a new season and the old timeslot from last season became problematic (like a ratings juggernaut aimed at the same viewers suddenly appears at the same time on a different network), or maybe a better one became available, the show gets moved.
4) If a show is doing well in a choice timeslot, it might get moved so a new show gets the choice slot in an effort to give the new show its best shot at succeeding. Generally speaking audiences will follow good shows wherever they go. Also, a good way to turn a bad slot into a good slot is to put a good show there.
5) If a show was doing well in its old slot but the network thinks it can do even better in the new slot, it might get moved to try and make it even more successful.
Don't leave a show on long enough to build viewers
History has proven that most series doing badly won't gain more viewers if they're kept running. In fact, they'll shed viewers. Every once in a LONG while a poorly performing show starts doing well. Those are the exceptions that prove the rule. (Viewers who are upset with Syfy because they feel we didn't leave a show on long enough often raise the example of Cheers to me. Citing one show in 28 years actually proves the point.)
Take a show off the air quickly
Leaving poorly performing shows on the air hurts the shows around them and hurts the overall ratings for the network. Also, the show was probably sold to advertisers by guaranteeing them a minimum number of viewers, so replacing that show with something else that performs better will help fulfill at least part of that commitment. If those aspects are factored against the very very very small chance the show might (possibly maybe) gain viewers, the obvious conclusion is reached.
Put a show on hiatus
There are a few ways hiatuses happen:
1) At Syfy we often take a hiatus between half seasons of our shows because airing all the episodes straight would mean a year-long break between seasons. Two half seasons every six months has proven a better way to keep viewer awareness up than one full season followed by a really long break.
2) A hiatus might happen around special events like holidays or the Olympics, so networks aren't airing new episodes of a show when no one's watching.
3) A hiatus might be a planned (or unplanned) break so a network can evaluate how a show is doing and make changes to improve it.
4.) A hiatus might be planned to help the production process...shows take a long time to make and sometimes the writers, producers, cast and crew need some vacation time.
Schedule similar shows opposite one another
Often a network might think a certain time and date might be good for a certain kind of show. Then someone else thinks that too, and neither is willing to give (it's a competitive business after all). Sometimes it's not ideal to leave a show where it is, but the network also can't rearrange its schedule to move the show. Sometimes shows that seem competitive really aren't.
Don't market a show well/at all
There is a finite amount of money and time available to market any given show, and within those restrictions shows are marketed the best they can be. (Same for the marketing of anything else by the way.) Often viewers won't think a show was marketed well because they either never saw an ad or don't think they saw an ad. Often they saw many ads and don't realize it. Or it might be the case that they weren't targeted with ads because the network knew they'd find out about the show other ways. As a rule, EVERYONE on the TV side wants to give show as much marketing as we can afford and we're always trying to figure out ways to get more marketing, or get more efficient marketing. Always.
A bunch of reasons here. First, viewers love to watch remakes even though people say they're sick of them. Also, part of the job marketing the show is already done because people are familiar with it. Creatively, shows might have a really great core premise that makes them timeless as long as they're updated for a contemporary audience from time to time. Possibly some REALLY BIG NAME loved the show as a kid and has an idea for a new twist, and viewers want to see things from the REALLY BIG NAME. Sometimes rights to a property are split up so one company owns the movie rights and someone else owns the TV rights, and one of each gets made. Of course, sometimes it's just bad judgment to remake something.
Remake a recent remake
Listen to the Nielsen numbers/Not listen to the great DVR numbers
The industry standard right now is Nielsen ratings, which are the best measurement tool that's proven workable at the scale needed (i.e. not just theoretically possible but actually able to be implemented and to get everyone to agree to use them). Ratings are the currency of the TV business at the moment, and they're the only way to do business. If a TV network didn't want to use Nielsens it'd be like saying they want to start an ice cream shop but they'll only take gold bars as payment, not the standard cash or credit. DVR numbers are a mixed bag. On the one hand people are watching the show, on the other hand, if they're fast forwarding through commercials, the network isn't making the money it needs from them to support the show. Counting them is tricky.
Don't understand a show
That thing you see in the show that you really love...the great characters, the charming premise, the new twist...someone somewhere at a network saw that before the show was a show, then made the show because of it. Which is why you're now seeing it.
Want a show to fail
If the network wanted a show to fail, they wouldn't put it on the air.
After reading this you might still think what networks do is crazy, or you might think, oh, okay, now I understand. Both points of view are valid, and what works for one show might not work for another. Networks use these tactics because they have proven to work in the long run, and as soon as they can figure out something better, they will. That's not much solace to a fan of a particular show I know, but at least you know there is some method to the (seeming) madness.
As always I'll try to stick around and address your further questions and comments in the comments section.