It depends as far as I am concerned.
There is the case of where a two or three word domain is concerned there are instances in which a typo 'might' be attractive, such as an example the domain name 'FearlessSheila' ('fearlesssheila'), in this instance dropping one of the 's' might be OK ('fearlessheila') , and especially if the term is highly commercial and the domain in question is already registered and the aftermarket price of the domain is extremely high.
Then there is the consideration of wrongly ordered letters in a spelling, this is particularly the case where the 'i' and the 'e' are reversed from the correct spelling of the word.
Of course you also have the case where letters can be replaced with a letter of similar pronunciation, 'c' and 'k', or 's' and 'z', are examples here.
Of course we also have in modern use the replacement of a letter or indeed a whole syllable by a number, think of the number '1' for 'l', or '3' for 'e', '4' for 'for'/'fore', '8' for 'ate'.
Yet another area is missing out letters altogether, this normally is in relation to vowels.
It also depends if the proposed marketing/advertising of the product in question. If the marketing/advertising campaign is going to be mainly internet or paper media print then the lettering can be played around with, letters can be mixed up quite a bit, but there are specific rules of thumb on what the human mind generally decodes from mixed up spellings of words (neither the first or last letter should be changed, and changes in letter order should remain within each syllable, etc..), but these are very nuanced in their effective use.
Truth is though that I would generally register a 'typo' myself rather than buy one - unless I specifically needed it or saw real value in it. (I have voted 'yes' because I might do.)
