Following their information search — or sometimes running concurrently with this process — potential customers start comparing the alternatives that your article has discussed. Again, the time spent in this stage will vary based on the type of purchase being contemplated. Choosing a restaurant might be as simple as deciding, “Well, I feel like Chinese food, not Mexican, tonight.”
For example, when a customer finds you organically through a Google search for example, that means you have some element of authority. When you have authority, prospects are more likely to enter into your funnel because they know that if they found you relevantly, that whatever it is that you're providing must be of a great value. That's just the nature of SEO and organic search. 
As you can see, each color-coded section of the funnel pictured above corresponds to a stage in the buying process. The widest tier at the top of the funnel represents “awareness,” the point at which potential customers are beginning their information search. The second tier is “interest,” roughly corresponding to the evaluation of alternatives described in the purchase process above. And, finally, the third and fourth tiers, “desire” and “action,” are self-explanatory.

If you’re running a consulting business, for instance, your clients already realize that they’re having certain problems around your service area – like disorganized spending (if you’re in accounting) or a high cost per lead (if you’re in marketing). On the other hand, if you’re running a software development business, your client could be having problems with absolutely anything right from the hours being consumed to other factors that affect deliveries.
Force moves the sales process forward. Areas of force include accurate and timely information, a good understanding of the problem, your ability to listen and overall responsiveness. Friction slows down the sales process. Essentially, when your prospect has to jump through too many hoops or faces obstacles or inconveniences throughout the sales process, this creates friction which makes your job more difficult.
In marketing automation, Ryan Deiss, co-founder of Digital Marketer, often describes the sales funnel as a multi-step, multi-modality process that moves prospective browsers into buyers. It's multi-stepped because lots must occur between the time that a prospect is aware enough to enter your funnel, to the time when they take action and successfully complete a purchase.