Don't confuse the automation of lead nurturing with the fact of nurturing leads. You absolutely need to ease prospects along, encourage discovery and maintain contact - full stop. But there are a lot of different ways to do it. Hubspot, Marketo et al are good tools - but they might not be what you need. Many people confuse tools with tasks or activities. Don't do that.
This is a really broad question… allow me approach just a part of it.
Email Marketing is one of the primary tools in marketing automation. This answer is based on our experience of over 400 email customers and 10 years in the space.
There's no question that lead nurturing via marketing automation generates results - leads. However, is your business set-up to respond to this new lead pool?
Most businesses are used to responding to leads from a comfort zone. i.e. inbound phone calls; contact forms via websites; word of mouth referrals etc. What these new platforms bring are direct leads via forms but also leads born out of online intelligence.
Before you can get value from those via online intelligence your sales team and processes need to create and apply a very different approach. This approach will be a new experience for both the sales person and the company.
In order to ensure you get the ROI from marketing automation you should plan the process and the how-to that convert those leads into prospects.
I would answer with a definitive "yes".
I've worked with a lot of companies that used to burn through their marketing budgets without turning many of their hard earned inbound leads into revenue. So much of their focus was on capturing the leads initially, but they had nothing in place to properly nurture the leads that did not close upon first or second contact from their sales teams.
The differentiator for these companies, when they did turn things around, was consistently a strategic lead nurturing campaign, primarily through email marketing and social media. These nurturing campaigns can be very time / resource intensive as they require a lot of planning, content creation and follow through. These reasons continue to be some of the main barriers for companies that don't currently do lead nurturing.
Hubspot, as with a few other tools, only helps to make the nurturing process more manageable and less overwhelming. If the more sophisticated software is too expensive, which it can be for many small businesses, then I would highly recommend starting with (at the very least) an email marketing campaign through a service like Campaign Monitor or MailChimp. A few well-crafted and properly timed email messages can turn a cold prospect into a hot lead as it keeps the prospect informed and your company at the top of their mind.