You do not have a person accountable for sales results. This might be you.
You lack a well designed sales process. You may have a sales process but you or others lack the discipline to execute it well and consistently.
You do not prospect. You or others may prospect but you are not doing it well or consistently to build a pipeline.
Your marketing is haphazard or misdirected. You might be making marketing far more complicated and costly than it needs to be to generate results.
Prospects and clients find you and/or your company hard to deal with. This might be reality or it might be perception; either way you need to fix it fast.
You never ask for the business. If the idea of asking for business stirs fear in your heart, you either need to get over it or find a person who can do it without fear. BTW- most people can get over this fear with a paradigm shift in their approach to sales.
You do not ask clients for referrals. The reason may and cure are the same as #6.
You sell rather than serve. Hard selling is now decades old and you have been left behind if this is still your style. Stop slicking your hair back and approach sales as a service to help others rather than a means to a fat wallet. Approaching sales with a service mindset will yield far more revenue and wealth than any hard sales technique.