Traditionally tourists to Turkey have bought a visa “sticker” at border control. If more than one plane landed at the “same” time the lines for the “visa” desk” could be horrendous.
Turkey has now introduced an e-Visa you can pay for online and print out (a hard copy is required); and it is anticipated that the option of obtaining visa sticker at airport will be withdrawn in Sept/Oct 2013.
To apply, or find out more, Visit the official Turkey E-visa site https://www.evisa.gov.tr/en/tour/.
With an E-visa you can avoid the visa queue, and simply show your passport and printed visa on entry/exit. Last I heard, the border guard will stamp your passport & write “e-visa” under the stamp (I expect they will soon be issued with stamps specifically for entry by e-visa – saving an extra 2 seconds writing time!).
The E-visa is available for tourism and trade purposes only.
Some tourists report receiving their visa within seconds of applying. At the time of writing (July 2nd 2013) the E-Visa website FAQ states “Your e-Visa will be e-mailed to you within 24 hours after completion of your application.” However, it is a new service, and we have all heard of new websites failing during unexpected peaks in demand – so personally I would want to submit my application at least 3 days before my flight.