In regards to SEO, is a site map important for a small 3 page website? I understand that it is not needed for the convenience of a user visiting the site, but will it help the search engines find it?
Google's John Mueller from the sitemap team had this to say about sitemaps when he answered a question on this site about whether sitemaps help for rankings (they don't):
..for really small, static, easily crawlable sites, using Sitemaps may be unnecessary from Google's point of view once the site has been crawled and indexed.
But he also said that there are reasons that you may wish to use a sitemap beyond getting your site crawled and indexed:
- Discovering new and updated content (I guess this is the obvious one, and yes, we do pick up and index otherwise unlinked URLs from there too)
- Recognizing preferred URLs for canonicalization (there are other ways to handle canonicalization too)
- Providing a useful indexed URL count in Google Webmaster Tools (approximations from site:-queries are not usable as a metric)
- Providing a basis for useful crawl errors (if a URL included in a Sitemap file has a crawl error, that's usually a bigger issue & shown separately in Webmaster Tools)
- If you use a crawler to create the Sitemaps file, then you can easily check that your site is crawlable and see first-hand what kind of URLs are found. Is the crawler finding your preferred URLs, or is something incorrectly configured? Is the crawler getting stuck in infinite spaces (eg endless calendar scripts) somewhere? Is your server able to handle the load?
- How many pages does your site really have? If your Sitemap file is "clean" (no duplicates, etc), then that's easy to check.
- Is your site really cleanly crawlable without running into duplicate content? Compare the server logs left behind by Googlebot with your Sitemaps file -- if Googlebot is crawling URLs that aren't in your Sitemap file, you might want to double-check your internal linking.
- Is your server running into problems with your preferred URLs? Cross-checking your server error log with the Sitemaps URLs can be quite useful. How many of your pages are really indexed? As mentioned above, this count is visible in Webmaster Tools.
It is important because you can submit the sitemap to Google via Google Webmaster Tools and that's probably the clearest and cleanest signal you can give Google that you exist and are ready to be indexed.
Is it necessary to have a sitemap for a microsite? Probably not, especially if you are already indexed. Even so, it's a good habit to get into as small sites that do well tend to not stay small.
Sitemap.xml helps Google to index your webpages particularly when you don't have many backlinks.
However, when your website begins to get backlinks, Google-bot often crawl your website and index your webpages easily. For a website with only 3 webpages, Google knows finding your webpages by itself and you don't need to specify a sitemap.xml via Google Webmaster Tools.
I built many small websites in a past without sitemap.xml and with several backlinks, Google always succeeded to index my webpages.
I speak about Google here but there is the same for Bing.
You got a lot of attention for this question and I thought I'd put my 2 cents in...
No one knows for sure if Google rewards for having a sitemap but what we know for sure is that sitemaps do help Google crawl sites when they are having problems crawling your site as well as detecting pages that they may have or not have in the index.
Personally I wouldn't worry to much about a sitemap on a 3 page site since Google will find those pages and I honestly believe that sitemap's do not reward to SEO why would they? if Google can find the Content. If Google can't find the Content then it does effect SEO but the fact you only have 3 pages I'm 99.9% sure that unless your site is badly designed Google will find those pages just fine.
It's worth noting that I have many sites without Sitemaps that rank just fine, I also have sites that have sitemaps but I generally use them on 'Big Sites' and small sites I don't bother because I can easily see if all pages are listed using
site:sitename.com In the Google Search.
Are all your 3 pages indexed by the search engine? Do you know what people search when coming to your site? Are you aware of how much time your site takes to load? Have you claimed ownership of your site?
If the answer of any of these questions is no, then please register on Google Webmaster Tools (GWT) and proceed to upload the sitemap, track search terms and claim ownership.