That's not incremental search, you're describing repeat search.
Incremental search means that the search is performed as you type the keys.
In VC++, for example, Ctrl+I begins incremental search. Then key 's' would search forward to the first instance of 's', then 'e' would search forward to the first instance of 'se' and so on. F3 would then find the next instance.
Seeing the results as you type is the major benefit. You can stop typing as soon as you've found what you want, or discover that there are no matches much faster.
When performing incremental search, the backspace key should remove the last character from the search string, not delete the selection.
colski