Google will only spider and index as much of your website as it believes it will use.
If your website is doesn't seem worth while then Google will not spend computing resources to analyze your site.
If you have 100 page you certainly want all 100 pages saved in Google. So what would make your website valuable enough?
Here are some ideas:
1. Deep Linking: Getting links to your site is great and most links will point to your home page. But it would be so much better to have inbound links to sub-pages and even sub-sub-pages within your site. Google usually follows all the links it finds, and when those links point to a variety of pages on your site it causes Google to index more.
2. Change the internal linking structure of your website: Google won't dig too far into your website from the home page. If it takes 5 clicks to get to some deep pages of your website Google probably will not click through 5 levels. You would really need deep linking to coax Google into going that far. The solution is to flatten the linking tree of your website. Have fewer levels to click through. If you can't change the navigation to reduce the number of levels then figure out which pages are less important and restructure with the more important pages only 1 or 2 clicks from the home page.
3. One of the most powerful ways to control where Google goes on your site is to include links inside the body copy of your pages. If you cannot change the linking structure then you can simply add links to the body copy of the home page that do the deep linking for you. With this approach you could effectively flatten your website without needing your web programmer to get involved.
Links from Twitter and Facebook count heavily now. You could create your own deep linking simply by sharing links on either of those services. Don't do too much linking at one time, otherwise it will seem contrived or mechanical, and therefore it will not help your efforts.
