This is my personal opinion:
also *SPOILERS*
The ending of The Hunger Games: Catching Fire was good. It reveled enough to keep the reader wanting to come back for the next book, but not enough to push the reader away.
There is a lot of action building up to the final moments before the book ending. And by the book being in first person point of view, we cannot tell what is going on to anyone besides Katniss. So any reader is unaware that Peeta is alive. There's always the possibility that he may be, but no one is aware from this. By doing this the Author creates suspense and keeps the reader, well reading.
For example, after Katniss shots the arrow into the shield she is knocked unconscious, thus leaving the reader wondering if the plan worked.
When Katniss awakes we find out that her plan did work. However there is more suspense because her home, has been decimated. And we, the readers are unaware whom, if anyone, has survived.
sorry I couldn't come up with more examples, it's been a while since I read the book
