Apart from an attractive packaging/presentation and technical solutions, the best way to be attractive is to be helpful. That means sharing not only tips and tools on how to manage the site effectively, picking the right solution, but helping your client navigate the digital world overall. For that you have to first identify who your customers are (webmasters, small/medium business owners, corporations, non-profits, etc). Then you can launch a blog and share articles and insights that might help them excel at meeting their business goals (strategies, marketing, useful software, etc). Not only you will giving good advice, but you will also be contributing to your own marketing, tapping into the new organic traffic.