I’ve never given much thought to this, and maybe that’s a sign of how well it was designed and imple­mented: the his­tory and (high-level) tech­ni­cal devel­op­ment of  text mes­sag­ing.

Would the 160-character max­i­mum be enough space to prove a use­ful form of com­mu­ni­ca­tion? Hav­ing zero mar­ket research, [the research com­mi­tee] based their ini­tial assump­tions on two “con­vinc­ing arguments”:

For one, they found that post­cards often con­tained fewer than 150 characters.

Sec­ond, they ana­lyzed a set of mes­sages sent through Telex, a then-prevalent teleg­ra­phy net­work for busi­ness pro­fes­sion­als. Despite not hav­ing a tech­ni­cal lim­i­ta­tion, Hille­brand said, Telex trans­mis­sions were usu­ally about the same length as postcards. […]

[Fried­helm Hille­brand, the ‘father of text mes­sag­ing’,] had an argu­ment with a friend about whether 160 char­ac­ters pro­vided enough space to com­mu­ni­cate most thoughts. “My friend said this was impos­si­ble for the mass mar­ket,” Hille­brand said. “I was more opti­mistic.” 

Nowa­days, with the ubiq­uity of text mess­ging and ser­vices such as Twit­ter I feel that there is lit­tle doubt that 160 char­ac­ters is enough to get across all but the most com­plex or impor­tant messages.