Displaying excerpt on your blog especially on your front page is preferable since it provides a fast loading time for your readers, especially those who would like to skim through your posts but not to wait for the front page to load some long and undesirable posts.

Not only that, if you use Google Analytics to help you track and analyse your site hits, this definitely will help you identify which posts are more interesting to your readers and at the same time increase the number of page views.

I found a few good articles on how to enable this, which may be of use for your blog. These articles give very clear and complete information on how to display excerpt on your front page and other pages as well.

Here are the links:

• Display Post Excerpts Only in WordPress
• Template Tags/the excerpt