Perhaps more so. If you?ve enticed people into reading that far, the end has to be satisfactory. Not a damp squib. Fiction and copy have that much in common as far as the readers are concerned. They want everything to end happily ever after.
With fiction it?s the culmination of everything they?ve read thus far. If you?ve done your job correctly they?ve become involved in your story. They care about what happens to the characters they?ve come to know.
The beginning is where you draw them in. The middle is where the story unfolds and keeps them guessing. If they?ve invested time in reading your words, you can?t cheat them when it gets to the end. All the characters you?ve introduced have to be accounted for. And the reasons for their actions explained.
If it ends with a twist they weren?t expecting so much the better. As long as it?s in context of course. You can?t just throw something in for the sake of it. It has to make sense otherwise readers will feel cheated. And of course it has to tie in those loose ends. There?s nothing worse than dangly bits with no where to go.
With copy it?s a whole new ball game. For one thing you?re dealing with facts. Or at least you should be. If a potential customer has bothered to read it, it?s because they?re interested in what you can offer them. In which case you have to ensure the end of the process is a natural conclusion to doing business with you. In other words they go away happy and satisfied with the outcome. And if they don?t you?ve wasted all that time and effort for nothing.
If someone goes into a supermarket and selects a basket of goods, they don?t expect to be confronted with an assault course when they get to the checkout. Or find the process of purchasing what they have is so complicated they?re left scratching their heads in bewilderment. They?re more likely to dump the basket and leave the shop.
Whatever you?re writing you have to follow it through to the end. If your enthusiasm starts to wane half way through so will that of your readers. It?ll end up as nothing more than a waste of everyone?s time. The only way to get people to come back is to leave them feeling it was worth the effort. That the ending lived up to all the promises of the beginning.