Catalyst Media Group is one of the easier companies on the London Stock Exchange to understand. It doesn't sell anything, make anything or offer any service whatsoever. It is simply a 20.54 per cent stake in Satellite Information Systems, or SIS.SIS provides live feeds of horse racing to almost all UK betting shops, while also making money offering outside broadcasting facilities to TV news channels.Catalyst then gets paid a dividend from SIS. Yesterday the company received £1.03m, back in December the dividend was £1.4m.For the six months ending on December 31st, Catalyst made profits before tax of £1.9m, up on the £1.7m figure for the same period of 2010.Net debt is now nil, and net asset value per share is 122p per share, an increase of 9.9% over 2010.The gift that keeps on giving, SIS, saw revenues rise 5.5% in 2011 to hit £116m, with underlying earnings of £23.4m.Michael Rosenberg said he was "happy" with the improvement in profits. The shares were up 9.1% at 11:25 at 67.67p.BS