I think you are crazy not to do followups. If you are slamming busy and have a killer backlog, then sure. If your arent billing 50 hrs per week, at your target billing rate for all your people, then you are not realizing your earning potential. I would say charge more and earn it with your salesmanship. In any sales interaction the sale can be 'won' even at a higher price (sometimes impossible obviously as there are pure price shoppers), it takes effort and structure to do so though.
Setting up a simple CRM, which can be done for free makes a huge difference in sales management. I wasnt always a tree guy, and managing the sales process was what I did. Having stages and 'set' contact points, with 'form' pieces, makes a huge difference in customer engagement and ultimately conversion.
A Customer Relationship Management system can make all the difference in the world. This can be as simple as an excel document or any number of net/software based graphic-user-interfaces from free and paid service provider. I would be more than happy to share some of my experience with this stuff with any of you guys.