A lot of great answers here. My advice falls squarely in the marketing area. Treat this like a QA problem. Look at the metrics of your ad campaign across each stage of the marketing funnel. Just because they are not converting does not necessarily mean you have a bad product fit.
So, in this case, your marketing funnel has the following stages:
1) Keyword targeting
2) Keyword ad copy
3) keyword landing page
a) Landing page copy
Your problem could be in any of these stages.
In stage #1 It could mean that the keywords you're using to target your ad aren't the right ones. This would lead to the wrong people with the wrong problems at the wrong stage of the sales process being targeted.
In stage #2 what you are "promising" the potential client in the ad copy isn't coming through on the landing page. This leads to a relatively high click through on the ad but a correspondingly high landing page bounce or lack of conversion.
In stage #3 Your landing page might be causing your problem. Maybe:
a) the copy isn't selling your product well. This would lead to either an immediate bounce from your landing page or an exit to your feature page and some "poking around" your site as they try to find the answer they thought they were promised in your keyword ad.
b) as Karl mentioned the price point isn't working for your customers. This usually leads to an immediate bounce from the landing page.
c) You're making it to hard for them to buy. No clear buy button or too many clicks to get to a payment option or your dropping them off at your main page and not your specific buy page. This would lead to either an immediate bounce from your landing page or an exit to your feature page and some "poking around" your site as they try to find the answer they thought they were promised in your keyword ad.
First thing I would do is talk to a couple of your best customers (at least 5 but better to be between 20 to 30) and ask them why they bought from you. Ask them what they needed, what they wanted from your solution. What they were worried about before they bought. Take the answers and put them together in a needs based value statement matrix. This is a basic algorithm that allows you to spit out the marketing answers you need. It looks like this:
Needs (logical) + Wants (emotional) - objections(why they wouldn't buy if it had what they needed and wanted) = your value statement.
So in your case ( and this is obviously over simplified):
Need = I need IT security for my company
Want = I want to not be hacked and held up by some shady dark web mafia hacker group looking like a fool to my CEO
Objection = I wouldn't use it if it was too expensive or too hard to implement it.
- The keywords would come from the need column.
- The ad copy would come from the need and want columns
- The landing page copy would come from your total value statement.
the second thing I would do is invest in some basic landing page software and create specific landing pages for your product that are outside the normal website structure of your mar comm website. (it can be of course accessible via the website but should not be beholden to it. This will allow you to mess around with the landing pages and change things up while not diving into complete website redesign.
I hope that helps.