Whilst more can be said in-depth regarding the nuances of the Cape Colony as a "settler colony" and its differences to the others, these extracts from a previous response of mine should be of some interest:

From a question about the general factors influencing settler migration to various colonies:

General Factors (The Bigger Picture)

Why exactly did to-be settlers leave the Home Isles? The answer might perhaps be found in several key factors. The first may be found in the conditions of the Isles themselves, namely the extreme instability which affected much of the British Isles for the seventeenth century. Constant civil strife, rebellion, repression, and civil war meant that migration was a means of escaping the carnage and seeking sanctuary beyond the shores of the Home Isles. Yet for a grand majority of the settlers, there was another motivator: economic opportunity. The poor harvests and economic depression back home propelled many single men (and in some cases, entire families or communities) to seek greater profit elsewhere. This was particularly the case with the plantations of the Caribbean, where many Englishmen came to seek a quick fortune working in the sugar, tobacco, or gold trades. Subsequently, this idea of a link between conditions in Britain and migration is strengthened by the fact that fewer settlers departed from 1700-1760, when the influx of African slave labour to the Americas and the stabilisation of affairs back home meant that the "white settler" had little need to seek economic security beyond the British Isles. We can see this pattern emerging again after 1760, when economic downturns back down and the publicity brought to America as a result of the Seven Years War prompted a new wave of migrants. Between 1760 and 1775 (when the start of the American revolution put a sudden halt on immigrant traffic), an estimated 125,000 people from the British Isles (mostly Scots and Protestant Irish) crossed the Atlantic.

Yet the economic conditions alone cannot fully explain the motive to migrate. Ideology also played a role here, in two distinct shapes. The first of these was the "elitist" ideology of free trade, which rose in popularity amongst the economists and manufacturers of 19th century Britain. Under this idea of "progress", the goal of economic improvement was second to none, and any social costs was seen as a necessary evil in pursuit of that goal. It was a fairly commonly-held belief among English economists of the day that the only way to solve Ireland's poverty at the time was by mass-migration, though preferably not to England. Alongside this ideology of the landed elite and the gentry, there was the popular ideology of property rights and a sort of "economic respect" which John Darwin outlines further:

"Notions of a 'just' wage, and of the respect owed to skilled work fuelled bitter resentment against 'industrial' employment and 'factory discipline'. More rooted still was the idealization of property, of the right to cultivate a plot of land if not as a main income then as an insurance against old age and misfortune...If migrants were pushed out by economic hardship or worse, they were also pulled out by the lure of free or cheap land, the huge social magnet that was dangled before them by rival destinations in America and Australasia."

This was developed further by the contemporary radical free trader Richard Cobden, who believed that settler-commerce would bring with it great influence from the Home Isles to the native populaces of a region, declaring in 1836 that:

"Not a bale of merchandise leaves our shores, but it bears the seeds of intelligence and fruitful thought to the members of some less enlightened community...[O]ur steamboats and our miraculous railways are the advertisements and vouchers of our enlightened institutions."

As such, it was this economic-ideological mix which often dictated how heavily (or indeed, how lightly) a territory would be inhabited by European settlers. Australia for example, despite its harsh environment and vast distance from Britain, was declared terra nullius (nobody's land) by the British who first landed on its shores. As a result, the rights of the Aboriginal populations to the land were often ignored by the settlers, and the British government continually faced legal problems when dealing with "native" resistance. The sheep farmers, convicts, and settlers of Australia had an entire landmass worth of land to (attempt to) profit from, and attempt it they did. John Darwin on this drive to push the settling of to-be colonies further:

"Claiming the land, exploiting the soil, remaking the landscape, putting down roots, excluding all rivals were all stressful endeavours: scruples were costly and doubts might be fatal. The hard racist edge of settler society was the product of fear and anxiety as well as of arrogance. It reflected the pressure, all but relentless, to move restlessly forward in case stagnation set in and the experiment failed. 'Populate or perish' became a political cry in one settler society. As a populist motto, it fitted them all."

Thus then, this economic consideration was key in the trends of migration and settlement in various parts of the empire, but do not be swayed into thinking that it took precedence over every other consideration out there. Whilst the "lure" of economic opportunity often formed the motivation for settlement en masse in the expansion of the British Empire, it cannot serve as the sole reason in areas where settlement was not quite as rapid or indeed, successful.

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