Always of interest to philatelists is the limitations on the stamps they wish to collect or study.
Stamps for small islands are usually released in limited numbers, for example, and of course for a limited time - the Mauritius 'Post Office' stamps being the classic example of both.
Sometimes, however, a country changes substantially or ceases to exist altogether and that has its own significance. For example, a boy who broke the record for being the Indian with stamps from the most countries relied upon the fact.
His collection was recognised as having stamps from 308 countries (he now has more) which included entries from (unified) Korea and Czechoslovakia, which no longer exist.
Rare stamps from such regions naturally become more sought after. An intriguing Gold Coast cover with a diagonal bisect sent to Belize brought £14,000 at a Spink auction late last year.
Other covers including a Gold Coast Winnebah 1883 (15 Mar.) envelope Per s.s. Lualaba to London beat its £4,000-5,000 guide price to reach £8,000 and a Gold Coast Mail Sent Via German Services 1895 (25 May) envelope to Chungking, China likewise achieved £6,500.
These were dwarfed however by a collection of colonial stamps, containing a selection of rare Gold Coast stamps along with comparable rarities, which fetched £40,000.
A successful investment for the collector, if that's what he intended.