PPC Vs SEO:

Some of the major difference between SEO & PPC is
In SEO the optimization process takes longer time to get a good result, where AdWords advertising is instantaneous in seeing optimum results.
With AdWords a client pays for each click a visitor makes on their advertisement but With SEO the advertiser need not to pay the search engine to get a higher position.
Adwords helps to generate sales and leads rapidly.
AdWords does not charge a fixed price for your advertisement. You can totally keep your advertising spending under your control, Like your budget & bidding of keywords etc.

SEO vs. PPC: Knowing Which Right Is for Your Website:
•How large is your website advertising budget?

In choosing between SEO and PPC, you first need to decide what size advertising budget your business can support. If you have no money to commit to advertising, you'll need to stick with free SEO methods. But if you have even a little capital to invest in PPC advertising, consider giving it a try because it offers a number of benefits, including:
oFaster testing.
oProtection from SEO algorithm updates.

One major weakness of SEO is that algorithms change from time to time.
When that happens, sites that have been optimized in one way can lose rankings
and profits practically overnight. But when you pay for traffic, you're assured
a steady stream of visitors, no matter what changes Google and the other search engines make.

•How high are the average CPCs in your industry?
•How competitive are the SERPs in your niche?
•You have more money than time.