Sprint today leveled a huge gun at the competition: it will give a year of free unlimited service to people who switch from other postpaid carriers to Sprint. The deal, detailed on Sprint's web site, requires switchers to jump through a lot of hoops and meet a wide variety of conditions. To start, the promotion will provide one year of free talk, text, and data with 10 GB of mobile hotspot per line. People who exceed the 10 GB mobile hotspot allotment will be throttled. Video can be streamed at up to full HD, music can be streamed at up to 1.5Mbps, and games can be streamed at up to 8Mbps. Sprint says it will throttle people during instances of network congestion, particularly those who exceed 23 GB per month. People who earn free service will still be on the hook for taxes and other monthly fees. In order to quality for the free service, potential switchers need to have compatible, unlocked handsets, and they'll need to purchase and activate Sprint SIM cards before porting their number to Sprint. Sprint says the SIM cards cost $3 each, with $10 shipping and handling. The actual SIM activation will be free. People who take advantage of the deal will not be able to upgrade to new devices for at least four months, and Sprint warns that phone features and network experience will vary depending on the handsets being used. Sprint will allow a total of five free lines per account. Tablets are not supported, nor are other connected devices. The promotion is available through June 30. The free service will expire July 31, 2018, after which Sprint will charge its normal rates for multi-line unlimited accounts. Auto-pay is required.