We face substantial competition across all our businesses, including our wireless telecommunications business. We expect competition to intensify as a result of the development of new technologies, products and services. We expect that such trends will continue to put downward pressure on the rates we can charge our subscribers.
Historically, there has been considerable consolidation in the telecommunications industry, resulting in the current competitive landscape comprising three mobile and fixed network operators in the Korean market, us, KT Corporation ("KT") and LG Uplus Corp. ("LG U+"). Each of our competitors has substantial financial, technical, marketing and other resources to respond to our business offerings. The collective market share of KT and LG U+ amounts to approximately 54.9%, in terms of number of wireless subscribers (including an aggregate of 9.8% attributable to MVNOs that lease KT's and LG U+'s respective networks), as of December 31, 2020.
Our competitors for subscriber activations include MVNOs, including MVNOs that lease our networks. MVNOs generally provide rate plans that are relatively cheaper than similar rate plans of the wireless network providers from which they lease their networks, including us. In addition, other companies may enter the wireless network services market. While new entries into such market have historically required obtaining requisite licenses from the MSIT, pursuant to an amendment to the Telecommunications Business Act that went into effect in June 2019, companies meeting certain regulatory criteria may become a network service provider by registering with the MSIT without a separate license requirement. Although such amendment has not yet resulted in any new entries into the Korean wireless network services market, it may have the effect of encouraging new entries in the future.
We believe that an increase in market share of MVNOs and the entrance of new mobile network operators, if any, in the wireless telecommunications market may further increase competition in the telecommunications sector,as well as cause downward price pressure on the fees we charge for our services, which, in turn, may have a material adverse effect on our results of operations, financial position and cash flows.
Our fixed-line telephone service competes with KT and LG U+, as well as other providers of voice over Internet protocol ("VoIP") services. As of December 31, 2020, our market share of the fixed-line telephone and VoIP service market was 15.8% (including the services provided by SK Broadband Co., Ltd. ("SK Broadband") and SK Telink Co., Ltd. ("SK Telink")) in terms of number of subscribers compared to KT with 56.8% and LG U+ with 19.1%. In addition, our broadband Internet access, Internet protocol TV ("IPTV") and cable TV services provided through SK Broadband compete with other providers of such services, including KT, LG U+ and cable companies. Furthermore, our IPTV and cable TV services are facing an increasing level of competition from global operators of online video streaming platforms, such as YouTube, Amazon Video and Netflix, and the video services offered by leading domestic online and mobile search and communications platforms including NAVER and Kakao, as such services continue to become increasingly popular to serve as a substitute to traditional television programming. As of December 31, 2020, our market share of the broadband Internet market was 29.0% in terms of number of subscribers compared to KT with 41.1% and LG U+ with 20.3%. As of December 31, 2020, our market share of the pay TV market (which includes IPTV, cable TV and satellite TV) was 24.4% compared to KT with 32.2% (including its IPTV and satellite TV services) and LG U+ with 25.0% (including its IPTV and cable TV services), and the collective market share of other pay TV providers was 18.4%.
Recently, the Korean fixed-line telecommunications industry has been going through significant consolidation involving major pay television service providers. In April 2020, we completed the merger of Tbroad Co., Ltd., a former leading cable television and other fixed-line telecommunication services provider in Korea, and two of its subsidiaries, Tbroad Dongdaemun Broadcasting Co., Ltd. and Korea Digital Cable Media Center Co. Ltd. (collectively, "Tbroad"), with and into SK Broadband. As a result of the merger and the issuance of SK Broadband's shares to the former shareholders of Tbroad with an aggregate fair value of Won 862.1 billion as of April 30, 2020, we own approximately 74.3% of SK Broadband's total outstanding shares as of December 31, 2020. In the same month, SK Telecom acquired a 55.0% equity interest in Broadband Nowon Co., Ltd. (formerly known as Tbroad Nowon Broadcasting Co., Ltd.), another subsidiary of Tbroad Co., Ltd., for a purchase price of Won 10.4 billion in cash. As a result of such transactions (the "Tbroad Merger"), we have become the third-largest pay TV provider in Korea in terms of number of subscribers as of December 31, 2020. In December 2019, LG U+ acquired a majority equity stake in CJ Hello Co., Ltd. and changed the acquired company's name to LG HelloVision Co., Ltd. ("LG HelloVision") to collectively become the second-largest pay TV provider in Korea in terms of number of subscribers as of December 31, 2020. Such transactions, as well as further consolidation in the fixed-line telecommunications industry, may result in increased competition, as the entities emerging from such consolidation and other remaining players in the industry may actively pursue expanding or protecting their respective market shares.
Furthermore, the Government has historically enforced regulations on cable TV and IPTV service providers that prohibited them from having a market share of more than one-third of the total number of subscribers in the relevant pay TV market on each of their respective platforms. In June 2015, the Government amended the regulation to impose the same limit on the market share of the entire pay TV market, including satellite TV service providers as well. Such amended regulation, however, expired in June 2018. There are bills currently pending in the National Assembly to abolish the previous market share regulations on cable TV and IPTV service providers. It is uncertain whether such bills will be passed.
Continued competition from other wireless and fixed-line service providers has also resulted in, and may continue to result in, a substantial level of deactivations among our subscribers. Subscriber deactivations, or churn, may significantly harm our business and results of operations. In 2020, the monthly churn rate in our wireless telecommunications business ranged from 1.1% to 1.4%, with an average monthly churn rate of 1.2%, which remained unchanged from 2019. Intensification of competition in the future may cause our churn rates to increase, which in turn may cause us to increase our marketing expenses as a percentage of sales to attract and retain subscribers.
Our physical security business competes with other large physical security service providers, including S-1 Corporation ("S-1") and KT Telecop Co., Ltd. ("KT Telecop"). As of December 31, 2020, our market share of the physical security services market was 34% in terms of the aggregate revenue of these three companies, compared to
S-1 with 55% and KT Telecop with 11%. Our information security services compete with other providers of similar products and services, such as Ahnlab, Inc., SECUi Corp. and Igloo Security, Inc.
With respect to the e-commerce business operated by Eleven Street Co., Ltd. ("Eleven Street"), 11st, our marketplace business, faces intense competition from various e-commerce providers, including online open marketplaces and social commerce operators such as Coupang, Gmarket, Auction and Interpark. We also face competition from leading online and mobile search and communication platform companies with e-commerce operations, including NAVER and Kakao, as well as traditional retailers with online and mobile shopping portals such as SSG.com and Lotte.com, home shopping providers with online and mobile shopping portals such as CJ Mall by CJ O Shopping, GS Shop by GS Homeshopping and Hyundai Hmall by Hyundai Homeshopping, and various online marketplaces for specific consumer segments or product groups. Our television shopping ("T-commerce") business, SK stoa, primarily competes with other home shopping providers such as those listed above, as well as with various e-commerce providers and traditional retailers. The industries in which 11st and SK stoa compete are evolving rapidly and are intensely competitive, and we face a broad array of competitors domestically and increasingly, internationally.
Our ability to compete successfully in all of the businesses in which we operate will depend on our ability to anticipate and respond to various competitive factors affecting the respective industries, including new services that may be introduced, changes in consumer preferences, economic conditions and discount pricing strategies by competitors.