[cr0sh]

Regarding "HeyLaughingBoy"'s comment - that market would be tubes of caulk and glue/epoxy.

While in the industrial space most use the common "gun" style applicator with the large tubes of product, and certain other manufacturers (3M in particular) sell custom applicators for industrial use for certain products (oftentimes at an insane markup) - there is the space for both the DIY'er and "handyman" (as well as commercial maintenance).

They will typically use regular squeeze tubes, especially on smaller projects where the larger gun-style tubes are too much or wasteful (because they may only use a small amount, and even when capped off, the tubes will dry out/cure relatively rapidly, especially at the nozzle end - making them useless and wasting product/money).

There also might be a market for automotive window glass installers for the sealants they use (and a/c repairmen?); actually tons of markets like this when you stop to think about it!