SEM is method of marketing a business with help of paid advertisements. Advertisers plan and bid on keywords on which their business ad should be displayed.
Most commonly its types are PPC (pay per click) and CPM (cost per impression).
In today's competitive world SEM can be a money spinner for business if done correctly. As SEM promotes sales, business should give priority to Agencies providing Search Engine Marketing Services.
SEM is a practice of understanding a business goal, keyword placement and creating ads to be precise.
SEM has the potential to grow business profit. With right agency a particular business/company can always be on top of Search Engine Result Pages. And ultimately more close to meet its sales goal.