1.) The site does not function without javascript. In most cases, this won't matter, but in some cases it will be a non-starter. This often causes significant accessibility problems for the blind.

1.1) I realize you're doing just about everything in javascript, but this means there is no way to share a link to a particular search. Using url parameters like most other search engines solves this issue.

2.) The modal and forced email entry when trying to "view more" and "view details" is unexpected and unpleasant. Though you certainly want to get email addresses from users, you're violating the principle of least surprise here, and many users will be uncomfortable with handing out their email address.

3.) The text/copy shown when forcing email entry is coarse and uninformative:

>"Great! We're happy you're enjoying our product. Please enter your email address to continue using Nova."

Is there a reason why a user would want to give you their email address? If you can communicate a reason, it's a better approach.

BTW, you might want to remove the "no@example.org" address I entered for testing, and you might want to do some verification of entered addresses (not easy, but doable).

4.) After getting the "Thanks!" on email entry, the "view more" and "view details" links still don't work.

5.) Your database of businesses is too incomplete, and your similarity algorithm needs improvement. (Note: a small number of database entries may be entirely forgivable if you're just starting out and are looking at your lengthy todo list with lots of data you need to import ;-). I tried searching on two company names, [Rocket EMS] and [Information Handling Services] as well as the common abbreviation for the later [IHS]. The first (rocketems.com) is a newer and specialized local company, and the second (www.ihs.com) is very well known and has been in business for more than 50 years. You returned no results for the two company names, and mostly incorrect results for [IHS].

(sorry, reading Matt Cutts of Google and similar search related sites has me in the habit of using square brackets [] around queries)

You did locate one of the many subsidiary sites (brand names basically) of IHS, namely "IHS Engineering360 Media Solutions", but not the parent company. Though the subsidiary site does earn some of its living through "Marketing & Advertising" (this tag is most likely derived from SIC codes), it's not exactly correct or complete. Since you seem to be basing your "similarity" measure on SIC codes, the "similar" companies listed are very dissimilar.

I'm not entirely certain what I should have expected from the phrase, "find similar companies" so maybe my expectations were too high?

Well, it may be a little rough in a few places at present, but a company similarity search engine seems really useful to me, and I wish you luck with it.

For example, when I put in my company - Indicative - you identify us correctly, but I don't see any other web/mobile analytics companies, only a bunch of completely unrelated companies - everything from digital coupons to banner ad A/B testing.