Чем больше слов, тем меньше они стоят.
You can imagine conversation as sequence of phrases "glued" by interest of participants. Each phrase summons another one or even two.
In contrast, there could be long pauses, especially in cases of absence of interest, participants unknown each to other or awkward situation. This is the case when russians says "разговор НЕ клеится". A little bit more rare usage is "разговор клеится". It's idiom, so, something like "он попытался склеить разговор" doesn't make sense.
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