Trap or get information
It depends on a few factors that you can analyze in each match:
- Some do this for the purpose of taking an ALL IN;
- Depending on the position, they just want to test the level of the villain's hand;
In my humble view, the main reasons are these; use as a trap and get information.
It's not exactly a re-review, but I'll give you an example that happened on the Cardschat Freeroll:
I from BB took a min raise with blinds of 15/30, I was holding a pair of 5s and called All In, you know what the villain's hand is? "AA" was eliminated at the beginning of the tournament. Trap!
But of course, recreational players still use it just because of the ease of pushing the button.
Good luck!