Discussion Title: CRM & E-Marketing

I am looking to either change, improve and research the best systems out there for your agencies. We are looking to push the email marketing side of things but target that marketing to very specific audiences, whether that is looking to buy, tenants or landlords and at each stage of the process from starting the application right through to handing over the keys. This down the line will help us with direct marketing and social media. The only way we can do this is if we manage peoples data correctly with a system that can log all their details etc - basically an estate agents CRM. I have heard of some companies using Salesforce to do this with some success but thought I would put the question to the community to see what other agencies are using to manage all of this?