Lead Generation, Nurturing and Conversion Through Social Media

I am looking for different ways to manage leads generated though social media. I was looking at HubSpot and Sales Force but they are kind of expensive and I am no where near that level yet. I was playing around with Lead360 but their platform was a little to amateur for me in terms of the lead nurturing emails are concerned. Then I was looking at Constant Contact but I think I would have to pay two monthly fees to use their email marketing and social campaigns feature. Infusionsoft has pretty much most everything I am looking for but I'm not at the level to afford $200 a month yet. I'm using Mailchimp in the meanwhile since it's free for up to 2,000 subscribers. I'm probably at about 100 subscribers right now. What do you think about Aweber? Can it to the same thing as Infusionsoft?

Basically, I want to be able to generate leads for my clients (I have 3 clients right now) using social media and using automated email marketing to convert or nurture those leads so I can help increase revenue for my clients through a new marketing channel they are not currently utilizing or monetizing. Any expert advice on this topic would be greatly appreciated. Thanks.