For marketing, sales, and promotions management positions, employers often prefer people with a 4-year college degree or even a master's degree. So, if you're interested in marketing, you need to go to college for 4 years. In college, you would major in business administration with a focus on marketing.
You should also think about what you want to do in marketing. Do you want to work in advertising (e.g., design ads, commercials)? Do you want to work in public relations (e.g., write press releases or organize corporate events to help maintain and improve the image of the company)?
If you would like a bachelor's degree in marketing it would take you 4 years.
I agree with this - in order to excel in this competitive environment, a 4 year degree is definitely ideal.
However, certain smaller organization in certain parts of the country may be ok with a 2 year college degree, but, the promotion opportunities may be limited.
I'd agree. Typically if you're talking about joining the marketing department of a large national consumer brand (e.g., a car company) or going to work for an advertising agency, you would need an undergraduate degree (4-year bachelor's degree). A marketing major would be ideal, but you could also major in other things like communications (maybe psychology?). You don't need to get a masters degree, but in the long-run, returning to school to get an MBA after a few years of work would be valuable for most people pursuing a long-term career in marketing.